Not only ads. Primary anti-scraping use today is obfuscation either as anti-competitive practice or hiding unlawful behavior like IP infringement etc.

> If the reason the site exists is to use ads, they’re not going to let you use an user agent that doesn’t display the ads.

They've been giving it the old college try for the better part of two decades and the only website I've had to train myself not to visit is Twitch, whose ads have invaded my sightline one time too many, and I conceded that particular adblocking battle. I don't get the sense that it's high on the priority list for most sites out there (knock on wood).

Adblocker is only few clicks away and a surprisingly large amount of users running one. So they might not like it, but they already letting plenty of users to use agent that doesn't display the ads.