In business ethic, you can't just get a free money ~XD
They provided you with the benefits, but off course every company or service provider don't want you or give you automatically credited. You must claim by your own, cause the things with automatically credited will costing somethings.
"That’s understandable, and I'm fine with it. They offer their customers bonuses and rewards, but they still hope that some of them won’t claim them. That’s also why some of them add a time limit after which the bonus expires if you don’t complete the wagering requirement.. I got your point!
You are also right that on most casinos, you have to claim the cashback manually, but in most cases, you can claim it on the website itself without having to share your information on third-party services or platforms like telegram.