That's the reason I usually don't deposit my money in any new gambling sites. Better only gamble on reputed site which already many experts verified their bets and proven safe to bet. In gambling any way we need only luck to win apart from that if casinos cheat then you will never see any winnings in gambling.
But how can you know if their site is reputable or not if you never deposit? You should at least try and play there to make sure that they are really reputable or not. Some people try to bring X site down by doing this kind of thing though. So we can't believe on some reviews too sometimes
Bitsler is a genuine site but yes I agree we must verif your rolls very often like 1 in every 10 bets. Obviously its impossible to just verify each and every bet as this would make gambling boring. This is one reason why I love to play on blockchain based gambling sites like satnonce ( now closed I think ) because there are no issues as such with those games.