I'd have left Twitch if I didn't find it more entertaining than current YouTube. No one should be surprised they're at pre-covid profit levels again because they tried to shovel way too many ads down people's throats.
Imagine tuning into a random stream and getting greeted by 3 ads before you can understand if you want to stay or check a different one. I've been frustrated enough that I just turn to something else altogether for entertainment.
There are some decent adblockers like TTV.LOL, which is a simple proxy to a country that doesn't allow ads. But sometimes those solutions don't work either. Ironically I just use Turbo while not paying for YouTube premium, but just as people don't pay for YouTube Premium, I understand not wanting to support Twitch for a variety of reasons.
Not that you should return to Twitch but if you ever need to there's this TTV LOL PRO add-on for Firefox/Chromium or you can just use a client such as Streamlink (with GUI and ttv lol support) for desktop or Xtra/Twire for Android with a custom proxy
This isn't true for all streamers, just those with partner contracts from Twitch. They are the ones that are required to run ads a certain amount, I think below that they have the option to run ads but aren't required to but also if you don't run any ads Twitch will just start putting in ads on its own. And theres no control from the streamers over ads that show when joining a stream, those are always there and in my opinion are more annoying cause it makes it more annoying to switch between streams.