Paizo has significantly reined in the excesses of high level heroes. There simply is nothing of the unbalanced "mowing over supposedly challenging foes" you see in 3E/PF1 (and to a lesser degree 5E).
Paizo did tilt the game slowly in favor of high level heroes. By that I mean that at level 1 or 5 it's a death sentence for a player character to duel a single monster of his or her own level (one on one with no interference). But at level 15 the biggest warriors in the group started being able to do that, and arguably at level 20 everybody could reasonably be expected to do it.
More generally, at the lowest level, a Severe encounter is likely too much for all but the most veteran tacticians of players. But at top level, not even Extreme encounters faze the party. (My rough advice, shift the encounter building advice one category higher at low level, and one category lower at high level. If you want a Severe encounter at level 1, 10 and 20, build what the guidelines call a Moderate, Severe, and Extreme one)
In the case of spellcasters this tilt is even more pronounced. At low level, spells cast from spell slots basically suck (except for the Heal spell). Sure you could get in an optimal debuff that provides value to the group, but a class like the wizard clearly lags behind a fighter, say, during at least 5 levels (I would say 9, many people over at the Paizo forums would draw the line at 7). But from circa level 11 the Wizard starts feeling like a "real D&D Wizard" again, and at the highest levels you can basically throw an unlimited number of low level mooks at any party with a good spellcaster in it - the martials can't kill monsters fast enough, but spells of levels 6 and higher certainly can.
The first tilt is arguably needed for the heroes to feel some progression, and it certainly isn't sufficient for players used to other versions of the game (except, notably, 4E). The second tilt I can't say I support. I would much more prefer if Wizards were more competitive at level 1, even at the price of making them less dominant at level 20. In this regard I feel WotC was more successful in balancing martials vs casters throughout the entire game. However, Paizo is clearly better at balancing heroes vs monsters, so in the end, there still isn't a single best game to play.