I use ublock origin on Firefox and have never seen an ad on youtube. No idea why people don't do this. I will probably eventually pay for premium but would be better off just supporting people through patreon directly.
How do you expect Google to keep YouTube running if you don't want to watch ads AND also don't want to pay for premium? I understand using adblocker on shitty websites (and you could argue that YouTube is one of those with frequent ads) but then you should pay for premium. Just my 2 cents.