GURPS I find is hard to pitch to people because it's very, very reading-heavy and has characters that take a while to build if you're still learning the ins-n'-outs of the game. Building a character in GURPS can take multiple days for me personally, but I am a slow character generator overall regardless of the system.
GURPS also lacks character classes or jobs like PF unless you kinda "build" them yourself, by picking and choosing what you want from generic rules the game provides and describes to you. It might be offputting if your group has the kind of players who would just like to stick to their class' core abilities/playstyle or follow a more linear pre-built progression path.
I'd say the thing I like most about GURPS as a system is probably also it's biggest downside, which is the sheer amount of content you could choose from to apply to your game or your character. It's easy to get option paralysis with it all.
There's a book for practically every setting, species, trope, ect you could think of. There's not a single character idea I've had that I couldn't build mechanically, but that also comes at the caveat of reading game material for multiple hours at a time to find every fitting trait or rule I could for these concepts to work. That process often involved hopping from rulebook to rulebook.
I'm sure if you searched around on some TTRPG forums you could find people discussing their pros and cons of the system too, probably much better articulated than in my reply here lol. I hope my answer still helps a bit.
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