Same gambling strategy can work in one gambling platform but this may not be true for other casinos.
When it comes to luck based games, then those strategies are nothing but fallacies. But you are right, some casinos will make it easier to apply a strategy while others don't. For example, to apply the martingale strategy on a dice game, you will certainly prefer to play dice at a casino which have an auto bet feature and some other advanced settings like lowering/raising the bet on win/loss..
Regarding Rtp, there are some methods to check real RTP of slot provider per game and gamblers choose which platform they prefer.
If the casino doesn't publish publicly the game rtp then, unfortunately, there is no reliable way to figure it out.