I 'm biased because I loved 3.5 and when PF1 came out I was like, "Wow this is 3.5 on steroids!". I was hooked immediately. PS1 was said to be like 3.75. I was hoping PF2 would be like 3.8.
A new edition is not just a new PHB. It's a chain of new products, and the change of rules must be deep enough to explain why the new books couldn't be made under the previous edition. Paizo, admittedly, had the chance to publish a 3.75 edition because of the schism caused by 4e, and pf1 came with a specific campaign setting (Golarion) and finally, as a third party publisher they could change what they wanted compared to WotC. But now they are going to be the successor of themselves and after so many books, it would be hard to justify, going with a "3.8" edition, much more than a new PHB, DMG, and, possibly, a new APG.
My main gripe is that pf2 seems to me more "Paizo 4e" than "Paizo 5e" or "Paizo 3.8". I liked, and still like, basic, 2e, 3e, pf1, 5e. Never liked 4e though. I hope I will change my mind about pf2.