The problem is, now, that any advertiser can run on any video. If I am watching a woodworking video I shouldn't get an ad for dawn soap. It would make sense for a brief ad on tools, or a wood supplier, or something which I might even appreciate because it lets me know something exists.
It's not ads. It's the increased quantity of them and the low signal to noise ratio. Ads are useful, being inundated with them is not. It's further made worse by the average youtube video's quality going straight down to nothing over the 10 years. It's mostly "professionals". At this point, I'd rather go back to watching TV.