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.

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.

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.

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