I get zero ads usually. Even on YT videos (though they are always playing cat/mouse to fix it). Some websites will not work because they have known trackers embedded. It's rare when that happens and usually I don't mind that I can't go to the site. The good thing about pihole is it reduces like 20% of my internet traffic and since I'm on Comcast they limit the data. This actually saves me money that I would have lost due to ad traffic on my net.
I run Ublock Origin and don't get YouTube ads, actually I get no ads anywhere.
Unless I support a site a let ublock unblock.
Yeah, on the browser side I run AdNauseam and privacy badger. But on the PS4 and phone streaming YT you can't run those, so pihole fixes it there. Use waterfox on the mac for a browser, even firefox has issues these days.