I can relate. However these days I have found a new life for those abandoned Pis: I install Pi-Hole [1] on them and set them up for family and close friends.
It essentially blocks tracking and advertisements on all devices, not just my computers with ad block. Just need to keep the block lists up to date every couple weeks, but it's honestly great.
A few weeks ago I switched to Ad Guard Home. Has been rock solid since. The big dancehaus it doesn't support the exact same filter files.
What I meant is it doesn't seem to parse the same range of formats, so it rejected some of Pi Hole's filters as malformed.
After having various weird network issues and instability on a different OS with Pi-hole (updates often broke), I switched to DietPi, and now my PiHole and OS upgrades are extremely stable.
The DietPi installer/configuration for Pi-hole sets up all the networking for you in the install "wizard", took all the weird networking headaches out for me
I use to run ZoneMinder on an old PC, but it was a bit flakey, way too crazy to set up for a home system; I had learned how to config and admin it over the last several years, but I was just plain tired of it. It's another great system for security cameras, but not really for a home, unless you have a ton of cameras that need monitoring, and don't mind the dedication of a beefy machine to the task.
MotionEye OS is more a distributed solution. It is possible to set it up so one install can monitor multiple cameras (in some manner - I haven't played with it), but I like it as a simple single IP camera turn-key solution. It basically can turn a Rasperry Pi into a cheap wireless IP camera that isn't locked down or tied to a proprietary ($) cloud system.
Using a RasPi Zero W and the cheapest camera you can find, you can build such a camera for under $50.00 USD off Amazon; probably cheaper if you shop around a bit more. The only cheaper option I've found (but it takes more to set it up properly) is the ESP32 camera modules that you can get.