It’s probably getting better older… and the only thing that would affect that is battery life because other than that it should be pretty similar to when you bought it new. Older phones lag bc new software, apps, movies need and a built to use a faster and better processor like on the newer phones. Especially if you spend sometime using an 11 pro or newer and the. Go back to using your XS. Max you’ll definitely experience and notice a difference in speed and lagging but again that’s just because XS was great for its time but especially with 5G rolling out it couldn’t keep up. for example my 11 pro max was and still is years ahead of it time. No issues with lagging and has been able to maintain similar amounts of productivity compared to when I got it in 2019, without lagging. I replaced the battery last year and it’s been great. If your a heavy iPhone user (other than light browsing calling & texting) I would consider upgrading. Only bc XS is great but long term I don’t think It would keep up