My country is one I've been working on for a while, is called Shotaland! The fundamental principles of the country are Privacy and Freedom of Expression. The ideas of personal freedoms are deeply rooted in every single part of the Shotaland government. If you're not hurting anyone who doesn't/can't consent, you are free to do as you wish in the privacy of your own home.
Tell me about your fictional country and feel free to ask others about theirs! I thought this might be fun!
I'd try to remain a benevolent dictator for life with the goal of transitioning to a different government structure which i think is better suited to a post-scarcity economy, with the main principle of governance being an extreme and immutable enforcement on everyone having equal access to information and rights/duties under the law. This would require a gradual phaseout of A LOT of things, such as:
Government office positions would follow technocracy principles, but act in an advisory role.
Legislation would be done though some variation of quadratic voting, with proposals costing more voting power than a family could accrue in their lifetimes with the intention of minimizing voter fatigue as much as possible. Voting power transfers should be possible, but only in one-to-all scenarios, such as pooling it towards a legislation proposal, maintaining a specific legislation active, or redistributing voting power so as to increase the majority opinion's voting power in a specific vote. Vote duration would be extended when voting power is spent against the consensus in order to mitigate the impact of last-second coordinated voting.
Taxation would change to a tax on a constitutionally-limited portion of capital, and the entirety of land value and externalities. This is necessary in order to ensure everyone fair access to opportunity, as the upcoming automation revolution will bring the cost of labor(and its bargaining power) to zero, with the only remaining factors to production being capital and land. Capital can be increased, but land can't - so the country would have to make the most of its land and taxing its entirety would (per georgist principles) give it an incentive to be used for efficient and productive purposes. The capital tax would be distributed evenly to every citizen as currency. Public companies could pay their tax by issuing new shares, which would also be evenly distributed to citizens. Land taxes would be used to improve the land, ensure deterrence against foreign invasion, and run the government.
The goals behind this are removing as many roadblocks to progress as possible, while providing everyone the ability to improve the country's progress (and most importantly, their own progress) and be rewarded for doing so.
Autocratic powers would be necessary during the entire transition period, and then 1-2 generations where the country would hopefully show significant improvement over other countries and itself to convince everyone the government system is better than the existing alternatives and should be kept that way.
~~Who am i kidding, all of this would realistically get me sanction-blockaded and gaddafi'd by external actors within a year.~~
Post-scarcity relies on complex global supply chains involving many different countries, and anything with that much complexity has inherent vulnerabilities. This is what lead to the bronze age collapse thousands of years ago. How would you make your system resilient against collapse?
There's actually not that much that can be done to protect against collapse during the transition period as the developed world already depends on 3 major things, none of which would have good workarounds during a transition:
The only viable workaround for the first 2 is avoiding WW3. The third one could be worked around by using nuclear fission as a last-chance energy loan to finance a full-scale energy transition towards renewables(or praying for a hail-mary in experimental fiends such as hot fusion or lattice confinement fusion). The opportunity windows for all of these are quickly disappearing and may be nonexistent in some regions already.
There are other global-reliance systems which at least have some potential workarounds (such as the networks of debt), but overall they're smaller concerns compared to these, at least in the immediate-to-medium term.
The main other major concern i have in the non-global category is subversion of the government structure, which i tried to harden the government system against by avoiding the use of representative-based democracy and by requiring laws to affect everyone equally, as existing governments have demonstrated distributing power, even among a few thousands of people, still isn't sufficient to prevent corruption.
The goal behind the waiting period before ending autocractic rule was having enough societal progress happen that enough people have enough of Maslow's hiearchy covered to protect enough against this subversion happening on the millions-of-people scale. Without this progress in place, masses would likely vote themselves increasingly more leading to economic collapse.
I couldn't find a way to get rid of the electronic communications demand. The implementation of the capital tax, UBI and direct democracy voting systems need too much data input/storage/output (roughly estimating within an order of a terabyte per year) to be feasible without that, even though the computing could be doable on government-operated computers (ranging from vacuum tubes to micromodules in the scale of integration / miniaturization - electromechanical and below is definitely out of the question).
Despite the problem of reliance on the above, post-scarcity doesn't actually need a global supply chain - having one just makes it a hell of a lot easier to achieve. Rather, post-scarcity only needs enough productivity to beat society demands on voluntary mass unemployment, and this has already happened on some areas such as agriculture through synthetic fertilizers (increasing production) and large-scale mechanization (decreasing labor requirements). This completed the last requirement in the biological step of Maslow's hierarchy at the cost of limiting crop variety - most of the bulk production is now on corn, rice, wheat and potatoes, all of which are susceptible to climate-change-induced-collapse.
Besides increasing production and decreasing labor requirements, other means to achieve post-scarcity are decreasing society demands (which has historically been done through practices such as senicide and other targeted forms of social/ethnic cleansing, though i believe can be avoided at the current technology levels), and increasing voluntary employment. These last two methods were a significant part in the elaboration of the principles behind my top-level comment's plans, as they're the major parts capitalism has failed to focus on.