
Originally Posted by
Jeeqbit
2.0 (ARR) takes you through 1-50.
2.1, 2.2, 2.3, 2.4 and 2.5 are ARR patches so they don't give much experience. They were released when level 50 was the maximum level.
3.0 (Heavensward) takes you through 50-60.
3.1, 3.2, 3.3, 3.4 and 3.5 are Heavensward patches so they don't give much experience. They were released when level 60 was the maximum level.
4.0 (Stormblood) takes you through 60-70.
4.1, 4.2, 4.3, 4.4 and 4.5 are Stormblood patches so they don't give much experience. They were released when level 70 was the maximum level.
5.0 (Shadowbringers) takes you through 70-80.
5.1, 5.2, 5.3, 5.4 and 5.5 are Shadowbringers patches so they don't give much experience. They were released when level 80 was the maximum level.
6.0 (Endwalker) takes you through 80-90.
6.1 and 6.2 are Endwalker patches.
All of these expansions and their patches are one giant, never-ending story. Many of the sidequests give additional context to the story, especially the blue ones which unlock things, but aren't required to enjoy and understand the story.
If you over-level, it doesn't matter. The only level that matters is the level of the Main Story Quest, because that blocks access to new areas and its content. The level of your class is only relevant if it's below the level of this quest.
You can try to optimize it by leveling secondary classes by switching weapon, but trying to min-max it that way is not fun in my opinion. When you want to level other classes, you can do it easily and casually by doing daily roulettes.