I've seen a few new people around since I started leveling with some newbie friends I dragged into the game with me. I've also seen people shouting for stuff that someone with a 90 job or high-level friends could solo (limit breaks, coffer keys, etc.).
I do think it's unfortunate that Abyssea makes it possible for someone to level a job from 30 to 90 without ever interacting with a single new person but I don't know if that necessarily ruined it. Subscriptions were dwindling long before Abyssea; all Abyssea did was provide a scapegoat. I think the exp boost and FoV fix was a step in the right direction in making the game newbie-friendly. It's easy as hell to duo/trio up to 10k or more an hour at level 20 or 30 now if you know where to go... which seems like something a forum like this could provide.
Given the exp boost, Fields of Valor, and Level Sync (as well as the upcoming AH merger), this game is a hell of a lot more newbie friendly than it was when I started four years ago. Abyssea doesn't matter; the people who leech all their jobs to 90 in Abyssea probably wouldn't spend a lot of their time in pick-up groups sharing advice with new people anyway.