YouTube is taking a hard line against ad blockers. There are a few reasons for this.
The problem with ad blockers is that they block ads. Yes, that's obvious, but people use ad blockers and that cuts into Google's profits.
It also cuts into the content creators' profits as well, as they get their money from Google. And if ads aren't displayed, Google doesn't get money from ads, and don't pass along money to the content creators. Google has a financial interest in playing ads. Ad blockers are against Google's interest.
On Google's YouTube Help pages, they give you their explanation of things:
Ads on YouTube help support the creators you love and let billions of people around the world use the streaming service. When you block YouTube ads, you violate YouTube’s Terms of Service. If you use ad blockers, we’ll ask you to allow ads on YouTube or sign up for YouTube Premium. If you continue to use ad blockers, we may block your video playback. To avoid the interruption, allow ads on YouTube or sign up for YouTube Premium.
Yes, blocking ads is a ToS (Terms of Service) violation. Yes, fewer ads means less ad revenue, of which some goes to the content creators. And the page goes on to offer instructions on how to turn off ad blocking on their Websites.
So, am I suggesting you give YouTube money by subscribing to YouTube Premium? Well, no. And yes. It depends.
If you choose to watch YouTube for free, accept the fact that it's an ad-supported service, and watch the ads. Skip them when you can if you wish, but don't block ads. Watch them.
Or, if you don't want to watch ads, use their YouTube Premium option to stop the ads. You get the added bonus of YouTube Music Premium included with the YouTube Premium subscription. If you already subscribe to YouTube Music Premium ($11/month), you may want to consider adding $3 and getting the $14/month YouTube Premium plan and omitting ads in YouTube as well.
My Streaming Life does include YouTube. I don't mind ads, generally. But if YouTube Music was a consideration, I'd easily recommend YouTube Premium. If you really hate the ads, it's almost worth it anyway.