But not all problems at a casino will be found unless the gambler has gambled at that casino, so gamblers will review the casino they choose to gamble at and they generally don't know the problems at all casinos unless they check in detail at each casino to ensure the casino system is fair and does not complicate the withdrawal process.
A wise person is the one who learn from other people's experiences and mistakes. So, if many users say that they had a bad experience with a certain casino or that it is a scam (they need to be trusted users or if they present undeniable proofs) then you don't have to test the casino yourself and repeat their mistake.
In case you did a research and didn't find any review you can trust and you don't have any other option but to try the casino yourself, then at least do it with a small amount of money.
You are absolutely right, one doesn't have to make a mistake himself before he or she learns, it is commonly said that experience is the best teacher, but this days, that idea or mindset have changed for some aspects of life, as it is wiser for a person to learn from other people's experiences and mistakes.
It's like myself when I was actively playing on 1xbet, this was before I got to learn about 1xbit, I never had any issue with playing on 1xbet, but after i learnt that 1xbit is a scam casino, and also learnt how they are linked with 1xbet, also along the line learnt that 1xbet is also selectively scamming their users, I had to immediately stop playing on that casino before I become a victim.
This is something I believe every gambler should emulate, and that is, always learning from other peoples experiences and mistakes; through their reviews.