I probably shouldn't divulge this since it risks this privilege disappearing, but Twitch is the one place I don't see ads, even though I don't use an ad-blocker.
I think some years ago, I may have had a flag set on my account which stops me getting ads. In the past I've given security@twitch a heads-up about some minor vulnerabilities, so perhaps it was a gesture of good will from twitch.
It may also have been a freak case of falling between the cracks when having "twitch prime" transitioned from ad-free viewing across all twitch to not doing so.
It took me years to realise that I don't see adverts on twitch when I "should", and I don't fully understand why not. I'm not sure who even at twitch I would report it to, as it doesn't feel like a security issue.