Why would you want security, if you get 'play integrity' for phones that received no updates since 2 years. Google's current security practices are more than dubious IMHO. Now they are not releasing any source for security patches for 3 month, to 'protect' vendors that are too slow updating. As if there is no chance for bad actors to reverse engineer those patch sets.
I have the strongest level of "Play Integrity" on a Xiaomi phone that hasn't received any updates since the beginning of 2020. Google Pay and co work fine. It makes sense when you remember that PI is not about security at all, that's just an excuse.