Most times I don't have to blame the casinos because most gamblers who go for this bonuses don't even have the patience to read the terms and conditions before going for it because if they do, then they would have understood that it wasn't going to be an easy task.
Nevertheless, I would prefer that the casinos make this terms very fair and not extremely against the player.
We can't blame the casino but must check what we've done to know what happened. If a gambler wants to get a bonus from an affiliate, they really have to be able to convince people that the casino is good and can be a place to gamble. However, people think that sharing affiliate links can bring them a lot of bonuses but that's not the case. They can get a lot of bonuses if people who join under them use big money to gamble so the bonus will also be big. But if they don't, they won't get a big bonus or even get anything.Nevertheless, I would prefer that the casinos make this terms very fair and not extremely against the player.
I also think it would be a waste of time if you just spread links or introduce banners on the website without guidance and introductions via video or streaming, for example you are an influencer it might be easier to attract lots of users, especially if you have lots of followers even though they are not gamblers but they will start gambling because they see you get money from the slot machine.
The best solution is to never contact those casinos and, in general, some commercial sites that advertise their services or products through referral links.