Some newer casinos might use the latest security standards since they’re just starting out, while the older ones might already have proven systems in place (or maybe outdated ones). At the end of the day, we’re handing over sensitive information like IDs, addresses, and banking details.
Actually it's really hard to tell, some casinos along with the trust they've build, they would definitely invest to modern securities since they don't want any harm in their reputation, as well as they would like to keep their players safe, on the other hand, there are some old casinos that don't invest that much since they are old. But there's also new casinos that has good and better security since they wanted the community to trust their platform by offering better security or handling KYCs, if I'm going to choose, I would choose the older casino but not the one that doesn't improve especially in security of the sites and of the players.