It really doesn't. Cheap phones have browsed the web just fine for a long time, now. Raspberry Pi makes some
weird hardware choices and have been suffering from it for a while. The insistence on SD cards (other manufacturers support eMMC or m.2 or both, and while RPi5 does now this has been the case elsewhere for A While) is the biggest problem with overall perf, including browsers.
I would expect the boards with the RK3588 to still be more pleasant to use than an RPi5, but the RPi5, used with an m.2 drive, should be significantly better.