mach1.9pants
Hero
The enhancement bonus on magical shields was absolutely necessary in order to balance the broken base math. A level 20 attacker gains +20 to hit baseline, even before factoring in their ability score bonus or feats or a magic weapon or anything. In order to get +20 over starting AC to balance that, you need a +5 armor and shield and ring and amulet. It was just nuts, and it ultimately led to AC becoming worthless past a certain point, as no amount of reasonable effort would ever keep your AC relevant.
Hopefully they have fixed the underlying math, such that those measures are no longer necessary. As long as you're adding the same level-based bonus to both attack rolls and AC (as in D&D 4E, for example), that minor +2 bonus from having a shield will remain relevant and meaningful indefinitely.
In PF2 you add your level plus proficiency (-2 if not proficient) to both attack and AC, so yes.