Parmandur
Book-Friend
Let's engage in a little nuance here.
In Pathfinder Second Edition a feat is simply something you choose. Ancestries and Classes have very few bundled features, usually only the bare minimum required to realize it conceptually. Instead players design what their fighter or their dwarf looks like. Some classes are particularly good at this. You get to decide how mystical, how athletic, or how kung fu focused your Monk is by selecting only the features you want. Some classes have subclass like options, but you generally get to decide how deep you want to lean into your subclass. A dragon instinct Barbarian could have a breath weapon, grow wings, and eventually transform into a dragon. They could also just have a flaming sword and have fire resistance and resistance to piercing weapons.
Archetypes allow to venture away from the themes of your class, although the thematic core stays with you. You never stop being a Fighter or a Barbarian. You also get to choose exactly what you want from them although you cannot invest in another archetype until you have invested 3 class feats in the archetype.
The big difference in how the two games approach character design is that in Fifth Edition you buy the whole cow. In Pathfinder Second Edition you get the individual cuts you want to. There are trade offs involved in either approach.
The whole cow approaches provides a compelling package of thematically appropriate abilities designed to work in tandem. It also makes character creation much simpler.
The select cut approach allows the individual player the ability to design exactly what they want, but it's up to them to make it all work together in play.
At the table things tend to work out largely the same. You have the abilities you have and must face the opposition in front of you. So far the at the table the table complexity when it come to combat feels pretty similar to me. Pathfinder Second Edition has a lot more defined noncombat abilities so it feels more complex there.
That's about the long and the short of it.