I use /r/all but filter out about 100 subreddits to make it work. Unfortunately a lot of them were once great but get now exploited with fake stories or low effort karma farmers.
When Apollo used to work (before the 3rd party apps purge), it would let you block any amount of subreddits - the first 100 it would block using the reddit api (which has that as a limit) and everything after, it would filter out on device. I think by the time it stopped working, I was blocking a couple of hundred subreddits.
