Why do we even need to compare Youtube and twitch ? Both cover the difference audience and both are popular in one way or another, however, Youtube is more watched as compared to Twitch. As per some data , Youtube has 2.1 billion monthly active users while only 30 Million Active users visit Twitch daily. So you can find the difference in number of visitors at both platforms.
However, when it comes to gambling content or crypto currencies content, both have some restrictions and those streamers are not given free hand on both platforms. Twitch bans content which included unlicensed slots, dice and other gambling games while youtube has a restricted policy over content related to gambling, drugs , alcohol etc.
Content creators and advertisers need to follow the policies given by these centralized platforms and also creators needs to find a more decentralized place on the internet where they can create content and stream without much restrictions.
Youtube doesn't just have videos, youtube has streaming as well for a while now. There has been a ton of people who moved from Twitch to youtube, and then even back, which means that you are seeing something that would be profitable for these people if they picked youtube and streamed their gambling there.
But, as far as I know youtube already has a ban for gambling streams, which means that both of these websites are out. It's clear that there is a need for gambling only (well you can add other stuff too but marketing point should be gambling) streaming service, that way all of these gamblers would go there, including drake, which would create a good marketing for them. Hell, Drake could start his own, and make money from that too.