it's not "pressure to conform" it's that you will end up gradually pushed out of friend gcs especially. it's not always intentional but there is 100% a certain amount of social isolation that usually results.
(p.s. this is actually a bit better than it used to be, everyone's a lot more comfortable doing a snap gc because it has most of the same features and the UX isn't dogshit like a mixed gc vs imessage.)