Only a support tech chiming in, so far I've found when it goes wrong, it causes errors or behaviours that are unusual and could be hard to trace back. Clients might be confused as to why their laptop isn't connecting to some services but their co-worker still can.
I've currently got an infuriating issue where the DNS on my modem just dies at seemingly random intervals. I set up a monitor using Uptime Kuma to let me know when it goes down, and ever since it just hasn't been a problem yet so I have no idea why it's going down. I might just set up a pihole and just work around the problem.
From my experience, if you're on iOS then Brave is the only browser I know of that includes a built-in adblocker (although I have my own issues with Brave).
If you're on Android, should be able to just install Firefox (or a fork like Fennec), tap the three dots in the app > Extensions > uBlock Origin
If you're otherwise using the YouTube app, I don't have much to add in that respect as I usually use Invidious or NewPipe.