yes, it’s currently ps4/5 and PC but when it launches on Xbox it’ll have crossplay on release. I also believe cross save exists but you have to purchase DLC specifically for the platform you’re on.
I’ve been playing Final Fantasy 14 for about 3 years now and got my partner into it a year ago, we both highly recommend it even if it’s just to experience the main story.
The community tends to be pretty active, there’s a lot of roleplay as well as end-game raiders. The lore is the biggest reason to play imo, it’s a hundreds of hours long adventure that has made me laugh, cry, and feel genuine empathy for some of the characters I’ve met. PvP exists but it’s not super competitive. PvE on the other hand is split into dungeons, trials, and raids. Dungeons are classic MMO dungeons with trash mobs and a couple bosses, trials are just a big boss, and raid tiers are 4 separate boss fights with the last one having a 2nd phase. There’s also different difficulties of content, but you do the normal version first during the main story or side quests.