why some online casinos have different odds depending on your account age?

Been hearing rumors that your odds on some games actually get worse the longer you’re around on some online sites. Seems wild, but I have noticed win rates dipping after a few months on certain slots and even live games. Noticed it mostly at the casinos pushing all the sign-up promos and cashbacks. Makes you wonder if the algo is tuned to keep you excited at the start, then slowly pulls it back once you’re a regular.

Anyone actually track this with data? Hard to believe the regulators would just ignore it if it’s true, but I wouldn’t put it past a few of these shadier outfits. Curious what folks have seen firsthand, not just the usual hearsay.