Linux

Stable just means no major version jumps in software that might break your current setup. That's important for operating servers, not desktops.

I use debian Sid (unstable) at work and never had problems. Most of the time I get updates prior to other distributions I am using.

At home I use arch (derivates, manjaro), with great success.

I would abstain from Ubuntu. There, I had problems, it is very opinionated and not in s good way.

In a general sense I would always chose a distribution that isn't too locked in to a certain desktop environment and provides updates, quickly.

I will say, in my experience, the “stability” boost that Debain has over other distros very rarely shows itself for a normal desktop user. It’s more for mission-critical/long-term business calculations where that stability makes a difference. Ubuntu LTS is incredibly “stable” for most desktop users, in that it will do what you want it to without fail, and will have safe, up-to-date programs (that last part is not always the case for Debian).

Do stable, use Flatpaks for anything you need to be newer. It works well.

Use Linux Mint instead, the 21.2 version is just around the corner.

Just be aware that "stable" in the linux world means "old." All of the software in the Debian repos will be much more out of date than some other distros like Pop!_OS, Fedora, or even Ubuntu. If you upgrade to newer hardware, or want to use newer software, Debian may not support it without jumping through some major hoops.

Debian is not easier than Ubuntu, the opposite is the case, you have to tinker around with some things to get them work how you want them. Usually you end up with a system which is more suited to your needs and preferences, but you have to put more work into it.

In terms of stability, it's not like Ubuntu LTS Desktop will just break down, I use it way over 10 years and it never end up in a broken state (well it did, but it was my mistake). It's more of a server thing, were you can just install updates without having to fear that something got incompatible.

Shouldn't be an issue. I see people recommending other distros but it doesn't sound like you are asking about that at all.

It also sounds like you understand the catch with Debian: older packages stick around for a bit. But, you can go to Testing or Sid.

Also, I am planning to use Ventoy for the boot drive. My device has UEFI, so is there any extra steps I need to follow to install the distro properly?

I've been running Deb 12 on my laptop for a year and a half and it's good. The one issue I have had is directly related to being on brand new hardware that wasn't supported yet by the kernel. Before that I ran 9, 10 and 11 with zero issues on laptops and desktops.

@test626 Debian is rock solid & I cannot recommend it enough. There's a ton of options that'll suit almost any computer spec. Go install it & see for yourself....

How do I know if my device actually works with all the foss drivers? Is there a list of hardware supported?

Stability does not mean what you think it does. Stable in Linux means "packages don't get updated, i.e. versions of things remain stable" and Debian is VERY stable, which means he's sometimes years behind in updates. As a desktop user you're likely to not like that sort of stability in your system, but that's great for servers since you can be relatively safe that things won't change that much when you do a system update.

Ubuntu is also very stable, and it supports non free firmware as well. But if you're happier with Debian go ahead, it's an excellent distro and at the end of the day distro choice is something completely personal that you're likely to change several times before settling down on the one you really like.

I would suggest Linux Mint instead, or using Flatpaks to update apps.

Now it's new, so you'll have less problems, but in two years, the situation might be different.

I love Debian! It is a project which provides a lot for the OpenSource and Linux community.

And yes, it is the most stable Linux you can have.
Personally I would suggest to start with a distribution with more actual packages like Fedora, Manjaro or even Arch.