Yeah, Youtube seriously needs to improve ad quality. I personally totally get that it's an expensive site to run and have no problems with the fact that it needs to turn a profit (not every site can get by on donations alone and that's okay). But the ads can get really bad sometimes. The majority are fine, but the number of scams and NSFW ads are still too high.
TBH, I just paid the extra $2 to go from Youtube Music to Youtube Premium because I really didn't want to see those ads and didn't wanna deal with figuring out ad blocking for a Chromecast. But Youtube Premium isn't worth it if you're not already using Youtube Music (I would not have paid $12 for it) plus you have to use Youtube a certain amount for it to be worth it. Plus, of course, it shouldn't be necessary to pay them not to see ads just to avoid seeing the bad ads.
And all this does nothing about Youtube recommending videos (not ads) that are unethical. They don't do a good job at curating videos. Heck, there's been times where they age restrict LGBT videos for simply having any LGBT references but they'll leave up crypto scams and hate speech filled alt right videos.