Naoki Yoshida's Comment in Regard to Jump Potions/Boost Potions

[Berethos]

what actually happens story-wise between 2.1 and 2.4?

I assume you're including 2.1 and 2.4 in that query?

Moogle primal begins to change what we know about how primals are created/their origin, Leviathan adds in information about the Echo, Ramuh shows us how a primal can be reasoned with in the right circumstances and aren't necessarily out for blood...and then of course the big one with Shiva being a mortal with the Echo becoming a primal. The Ul'dah political arc begins in earnest, which is what we get caught up in that lands us in Ishgard for a time. The Garlean spy arc starts, which may yet bear fruit as a story element since we're going up against Garlemald elements in 4.0. The Doman refugee arc happens, which sets the foundation for us eventually heading to Doma, as well as juxtaposing them against the Ala Mhigan refugees and their plight.

So the answer is quite a bit happens.

[Lambdafish]

snip

None of this is actual meaty plot though, rather setup for later plot events (a lot of which are just excuses for Ishgard to happen), we get a bit of background on what a primal is, and we get a bit of Doman refuge subplot (which didn't actually affect anything other than introducing the Domans to us as characters). These threads can be explored more in Stormblood, but the actual explanation as to what happened in these 50 or so quests can be summed up in about 1 or 2 minutes. I'd actually be tempted to exclude 2.4-2.55 from this as it is the lead up to Heavensward and contains a bit more plot than the other patches, but considering how old the content is, it should also be made into a summary.

[Naunet]

So the answer is quite a bit happens.

Honestly, this is a big part of the "the story feels boring and pointless in ARR" problem. So many tiny threads that don't get any real development and feel completely disjointed from each other. It's not very good storytelling. You pick up one thing only to drop it a moment later for the next key interest only to drop THAT a few moments later for something else...