I think the issue is that the more users these instances have, the easier it is for them to get throttled/banned by the services they want to use. I self host piped and it works 99% of the times
Also some services are frequently changing stuff or just making it impossible to have an alternative frontends
Same with all of these other frontends like invidious, teddit, rimgo, bibliogram,
This you?
Besides which... it's well understood that all of these apps are brittle as in they stop working every other day when youtube changes whatever thing so they stop working.
In the case of newpipe for example, if you install from the app store or even f-droid the version there will be a few weeks old and just won't work. The best approach is to install the apk and allow it to update itself when a new version is released. I've been using newpipe for several years in this manner and it's very reliable.
Er go, if it doesn't work for you, you're doing it wrong.
I imagine you're exaggerating but if not then I'd say that's a tad extreme. That being said, their official setup guide does provide steps on how to install it but I think if I didn't have prior experience with some of the software it mentions I think I'd struggle so maybe a different guide by someone else is better?
However these obviously require having something that this can be run on, like a VPS, which aren't free, so that is another barrier for entry to consider.