however its relatively rare that an ad company provides a bunch of services I want to use. The only exception i can think of is google.

obvs its hard to avoid gmaps because the alternatives are beyond godawful (no, openstreetmaps, i didn't want to go to the coffee shop of the same name in connecticut, I wanted to go to the one 3 km away), but for youtube I use a python tool called youtube-local which is very very effective, strong rec. Im sure google will defeat them eventually, but so far all of the incremental "block a little of this, block a little of that" stuff the g-man has been doing has been bypassed within a few days. Viewtube is also pretty easy to self-host, but they never quite figured out how to make the UI work.