Leveling to 99 is rather fast. Once you get the limit breaks out of the way it becomes easier to take all jobs to 99 if you want.
Instead of partying, people go to areas and party or alliance and do Grounds of Valor pages together. Mid-levels is kinda meh, but once you get to 99 and get your empyrearn armor, weapons, and atmas and abyssites to help your character out while in Abyssea zones, you tend to wow yourself with what you can accomplish.
If you're asking if its the same game from 2010 before Abyssea... no.. it's not. The changes were quite dramatic actually. Anyway, there is plenty to do to keep yourself busy while playing FFXI. Still plenty of challenging NMs, Bosses, Expansion Pack battles (Albeit they are easier where as a party of 75s was needed, and now maybe 3 LV 99s at best instead). Anyway, it's up to you if you come back.
I didnt think I would like all the changes, but I'm still playing after 8 years. I suggest at least giving it a try.
If you want a linkshell, look me up!