The worst thing is that gambling companies are free to ban you if you win too much.
So if you're still there it's just because you're being milked.
There's a a giant market for second hand accounts on betting websites for this very reason.
There are many jurisdictions where the companies are not allowed to ban 'winners', but the companies often respond by lowering those users' bet size limits.
This is my favorite line to bring up amongst my gambling addicted friends :)
They are not big fans
Not only winners but anyone that looks like to know what is doing.
By that I mean that they try to detect and ban any pattern that may be math / ML derived or arbitrage seeking.
I have been banned on an account that was loosing money (around -15eur) and the bet was 2.96eur - yep fractional bets is a big no - no.
So while it is possible to find better odds and win in the long run based on stats and ML with a 3% - 5% profit they will ban you before you do.