I tried to hint at this being a problem also when I bought them new, but I can see that it wasn't to clearly written.
My point is that my current iPhone is the first phone since my Samsung S2 that hasn't disappointed me by being slow more or less immediately after unboxing it.
iPhone 7 I had is noticeably laggy with maps and other heavy apps.
Meanwhile my Samsung S10e (equivalent to the XR) has more than sufficient performance and has a better screen for a lower price.