When FFXI, a game held back by PS2 limitations and one that keeps character server data that has existed since 2002, which means you can't use the "XIV has more players" excuse, can have more than 700 inventory slots per character, I find it extremely hard to believe that XIV is limited by their "servers."

Now, admittedly, the last 200 added inventory did finally start adding to load times, but unlike XIV, you can view all of your inventory data at any given time. XIV doesn't suffer from that problem.