I would say PF1 is a bit more streamlined than 3.5 in general. Especially it has a quite good online srd: d20PFSRDI said 1e, but I want to unpack it a little for fairness:
1. I am not directly very familiar with PF1e, but I was familiar with D&D 3 and 3.5 and nothing I've been told suggests they're different in any significant way in complexity as such;
2. I consider the more special casing something has the more complex it is, and I actually think that weighs in as much more more than actual complexity in general mechanics.
I would say PF1 is a bit more streamlined than 3.5 in general. Especially it has a quite good online srd: d20PFSRD
When you look at that and at classes like a fighter: Fighter – d20PFSRD then the base classes are normally easy to understand (not truenamer strange things), but it also has many advanced options etc. (which make the classes long like the advanced weapon feats).