Why you are assuming that they won't last long in youtube? Are you expecting that youtube is going to do the same as twitch did? No I don't think so because I've seen different contents in youtube and some can even be called inappropriate but they haven't been removed up until now.
Other than youtube, there are other streaming sites out there which are not strict as twitch. They can always use that. They can also create their own streaming platform as you suggested. It will never be a problem for them since they have a lot of money. They can hire a good website developer and then run some promotions. Pretty sure that many top gambling sites or those who got removed from twitch are going to migrate there.
SteveWillDoIt was advertising Stake and it had been banned from Youtube (now he's on Rumble). So I think Youtube will also ban other glambing streamers from Stake if they try to migrate there.
Regarding other platforms, I don't think viewers will subscribe to a new platform just to see streamers gambling sponsored money on slots or roulette. People watch them because they stream others things usually. But I don't think many people are interested in channels fully dedicated to gamling.
They may, I didn't know that youtube was also banned, but I believe that it depends on the streamer and what they do to get the viewers. Are you telling me that drake could stream "anywhere" and I mean literally anywhere and can't find viewers?
Of course he would be able to find some viewers no matter where he streams, I feel like Eddie could do a smaller version of the same thing, of course not as much as Drake but still find some viewers, and that means it is going to be easy to handle. On the other hand, if we are talking about you or me, then it is going to me hard because we wouldn't get a lot of viewers anywhere, so it depends on their fan base, not where they stream.