I also agree with you. Casinos would not create specific accounts with privileges to be able to change the results of a game and give such accounts to streamers. What happens is that streamers have a lot of money and time to play for many hours, so they will be able to win with high multipliers.
That is a very brave statement to say the least. As I said before here in the thread, what keeps a casino from tweaking the account's winning probabilities without letting the streamer know? Just think about how authentic the stream will become when the streamers doesn't know about it because they really believe they've cracked the golden formula and the casino is a highly profitable to go to for gamblers. Honestly I think the incentives to do that are so strong.
Yes they have a lot of time and money to play with, but when they go live there is no way to influence the outcome for them. And if it was a losing game because the house edge applies, then the longer they play the less they should win. It is usually those who have a couple of once in a lifetime moments who make it out with more money than they went it. I am talking about big money here.
But what OP said is there all of these streams taken together have an usual high success rate. I haven't watched any of those streams or highlights in quite some time, but I remember it felt skewed. Why would there be hardly any, if any streamer without profits? All of them are grinding with sooooo much success that I believe it can't be true statistically. It can be true for a few streamers, but for essentially all of them?