I've got a three year old OnePlus 5 and I've yet to encounter a single app that has been slow, so I'm not sure what value a faster phone would have for me. The only reason I'm considering upgrading is to have a better camera.

One overlooked consequence of a faster chip is less strain on a battery and thus longer battery life. While it may not necessarily affect the perceived speed of apps, it has this significant benefit to the user.

Real life performance and experience differs a lot. A cpu is part of the reason for speed but so are many other factors. It depends on your use case too.

That actually sounds, verbatim, like what Macintosh users used to say to PC folk back when they were on 68000 or PPC.