I know this seem like a typical "Your opinion man" post but honestly, is there anything really useful beyond hosting an adblocker? (read: complementary, not found elsewhere, that enhances own's personal needs and/or life as a whole). And yes, I'm aware of what can be hosted -- picture editors, video editors, webtops, dhcpcd, emulators, and so on.
But the question is -- why I'd need all that if these stuff can be found on any ordinary PC out there? Even phones. Hell, even on a smart tv. That is like "trying to reinvent the wheel" for no necessary purpose other than "to look cool". There's also "because its fun", but is it really fun doing pretty much the same thing over and over again? There isn't a "learning gap" between these hosting options -- all of em have (pretty much) the same procedure to get things running.
With that said... I've been trying really, REALLY hard to host more stuff but I can't go beyond hosting (only) an adblocker.
I think what you’re asking is not so much about docker, but rather about self hosting in general. If you don’t want to do that, you probably don’t need docker. If you do want to run some services, you still don’t need docker, but using containers can make it easier to manage. If you want to use containers, docker is one way to do that.