IMHO Arch is actually a great choice. They do have a minimum update frequency you need to maintain (I don't recall exactly, I think it is somewhere between 1 and 3 months) but if you do, and read the news before updates (and you are usually fine if you don't, usually the update will just refuse to run until you intervene) things are pretty seamless. I had many arch machines running for >5 years with no issues and no reason to expect that it would change. This is many major version updates for other distros which are often not as seamless.

That being said I am on NixOS now which takes this to the next level, I am running nixos-unstable but thanks to the way NixOS is structured I don't need to worry about any legacy cruft accumulating from the many years of updates.

And after all of that I don't think it really matters. I think any major distro you pick, weather stable, release-based or LTS will be fine. They all have some sort of update path these days. (unlike in the past where some distros just recommended a re-install for major updates).