“Quite within the realm of someone who’s got some computer skills” means “inaccessible to most people”. I don’t mean to sound like an ass about it, but most people just don’t care enough about this stuff to invest even a bit of time in it (nevermind the upfront cost for a Synology or Qnap NAS).
Sure - but you’ve got to start somewhere. There are a lot of people who aren’t experienced sys admins who are buying raspberry pis or arduinos and they are probably really good candidates for self-hosting some of their services. I was surprised to find my neighbor (who’s a PM with a physical security system company) trying to do something with chatGPT, at first I was a little dismissive because i figured she was just typing prompts into the website, but in reality she was having issues with the python bindings and getting her virtual environments straight. If you can get to that point, you can surely self host stuff.
I run git locally for some of my projects and that was trivial to set up - I think anyone who’s used github would have comparable skills to self host gogs or gitea.
Certainly it’s somewhat expensive, but people spend a lot of cloud hosted services too. I’m sure in my house we’re dropping over $100/month on dropbox, chatgpt, google, adobe and probably a half-dozen smaller ones.