Actually, I do believe that the casinos have the payout margins they claim to have and that is what matters.
In my own tests (which are by no means conclusive as none of us can perform accurate tests) how you play can help you.
If you go in with a set budget, a set time limit, and you stop playing the second you have won x amount of money, you can enjoy a bunch of entertainment for not very much money. And it could happen that you get lucky and win something, which you need to withdraw at once.
That is sensible gambling and if you practise that you can have a whole bunch of inexpensive entertainment.
That’s the way I see it.