I was a bit like you until I canceled Prime because of the price hike. I hate to say I might go back but trying to hold out for a while out of principle.
But I have a Pihole and nothing I’ve done has blocked YouTube ads. It seems to be the case for a lot of people because YouTube hosts the videos on the same server as the ads so if you block the ads, you block the videos.
I keep checking every so often just to see if someone has a blocklist that works though.