In our current PF1 campaign the PCs are now 16th level. Most of our campaigns get that far, or further. So it can be done.Ironically, I wouldn't run PF1e on a bet (too similar to D&D3e which taught me that it was essentially unrunable at higher levels) but I feel like I could do it with PF2e. I honestly get the feeling its harder on a player than a GM in many ways.
On the other hand, the amount of mind-caulk involved (re-stating monsters on the fly, throwing out stuff that's more trouble than it's worth and generally weaving around all the pot-holes) means we might actually be proving your point.