You could implement plenty of ways to access it, Cloudflare is just one of them. I made this guide to achieve the goal of self-hosting matrix bridges for people who are already familiar with Cloudflare and have a domain behind it, but it's not something that is mandatory to have for a similar setup.

Cloudflare Tunnels are useful to connect to the server without exposing your ssh port to the internet, and Cloudflare Workers to add .well-known files for federation and Sliding Sync proxy if you don't have a way to serve those files easily.