No small streamer should have to think about dealing with pre-rolls. It hinders growth and discoverability. It's likely that most small streamers are just starting to figure out how to retain an audience. So having to juggle between bringing new people and keeping those who were already there is an unnecessary job that only brings more anxiety.

Affiliates (or maybe just streamers with less than 10 simultaneous average viewers or so) could have a lighter ad schedule. For example, in order to disable pre-rolls, streamers would need to run 1min30s of ads every hour. That would be a good way for the streamer to get used to taking breaks while it could also be enough of a reminder for the viewers that they are supporting that content creator.

Forced ads on someone trying to find out if that livestream with 3 people watching will be a good place to hang out doesn't help anyone. It generates virtually no income for the streamers, it's a bad experience for the viewers and it has a fraction of the effect the advertisers are looking for. Needless to say, this is not good for Twitch.