I'll concede that I don't know Pathfinder first edition at all so I can't genuinely speak to how accurately they conveyed it. I'm just going by what I've heard people say. Though I personally LOVED the kingdom-building mechanic in Kingmaker and the crusade mechanic in Wrath of the Righteous. I loved getting time to just focus on kingdom building or taking a break fromthe main game to go crusading with my armies, so I think it may be a matter of taste. Or maybe it just happens to hit my specific thing that I like in games.
It's very much D&D 3.5. They optimized it further, but it is very unmistakable continuation of the same system. If you read introduction to core book, they even (almost) plainly speaks of it. Only to avoid legal issue they worded it as "3rd edition of world's most famous roleplay system". And yes, as hard as it is to believe now, back in the days Paizo and WotC still maintained very friendly relationship, and not been at each other throats.
Even though Pathfinder practically started with WotC ruining their own reputation with release of 4th edition. As both players hated it with passion, and many D&D devs also hated it. Leading with very big exodus of D&D devs from WotC to Paizo, and other studios.
Not second edition though. Even though it's still unmistakably D20 system, and with very much D&D-theme (less D&D-ish with upcoming 2.5 revision, again, stupid legal issues). 2nd edition nevertheless was built from a scratch, with very high focus on a game balance. Although simplification as well. In many ways PF2e actually achieved what WotC failed with 5e. More simplified system, but at the same time not nearly as broken. Though that of course if very surfaced coverage of both systems.
