Half of the content on YouTube could be considered to be an ad by itself. Also sponsors are being advertised regularly within videos which I would consider to be ads too

There's always SponsorBlock: https://sponsor.ajay.app/

It strongly depends on the kind of content you watch. I watch a lot of YouTube, but hardly any of it has sponsored content.

A lot of the videos I see have ads in them, section whith "this video is sponsored by this and that". That's definitely an ad. I would say most new (past few years) content by established channels has these. Some more obnoxious than others.