You get no random ad content which just cut into the feed at will, which makes for a somewhat better experience. But there's the inevitable "NordVPN will guarantee your privacy", "<some service here which has no ads and was made by content creators so you don't have to look at ads if you subscribe but hey all our content is on YT but with ads and here is an ad>" ad.

There is no escape. I actually pay for YT premium and it's SO much better than being interrupted by ads for probiotic yoghurt or whatever. I know there are a couple of plugins out there which I have not tried (I think nosponsors is one of them) but I really don't think there is any escape from this stuff.