If you are playing gambling because of the search for fun and not thinking about winning or fairness, you don't have to verify every bet because that will reduce your enjoyment in playing the games.
But you can verify by yourself to find out if their system is fair or they cheat on you, so you can report to the support system if you found it.
I think verifying the system is fair or not will need to spend some time to check, and not all people want to do that.
But if the gambling site is recommended and many gamblers trust that site, we don't have to suspicious about them because they won't do something negative that will make their members leave them.
The thing that can make us disappointed is when we lose our money in gambling, making us feel sad.
I agree with you, if we play gambling for entertainment purposes, usually do not think about fairness. So we don't need to check
every bet we have done to find out the fairness of the gambling site. Moreover, we do choose gambling sites that are popular and
trusted, so gambling sites reputation is guaranteed well. Because gambling sites have a good reputation, I believe they will be fair,
so there is no need to verify fairness.