@theredscreenking My understanding is that RTP is controlled by each provider. Casinos can only choose the RTP version of the game that they want to offer.
Games like Starburst have standard RTP versions, for example, as well as low and high RTP versions - casinos may choose whichever they prefer to host. That's why you'll find casinos with 96% RTP Starburst and others with 94% RTP Starburst.
It's better to look at RTP as a way to determine how potentially profitable a game is, rather than taking into consideration slot memory or previous rounds, in my opinion. It's not just about how much money you win, it's about how much money every player wins and loses. You may be one of the lucky ones to make a profit, but it all evens out for the casino in the end.
Also, consider that casinos usually have a winning limit for non-jackpot wins. Say you're lucky and win $750,000 in a 50,000x round. That would count as a non-jackpot win. The casino may have a limit of $250,000, so you would miss out on $500,000.