YMMV but it unironically gets good in the first expansion and the third expansion is actually great. However it is a very lopsided experience so I guess I wasn't left wholly satisfied
I've felt like every expansion is better than the last, but I also feel like ARR is really boring and that in general all of the updates to classes and dungeons have made the early game content worse with time. There isn't a single class that feels good to play at level 50 or 60 anymore, all of the gimmicks from old dungeons have been smoothed over leaving nothing interesting or memorable behind, after the initial "new player experience" where you learn the basics of the game you then have to play about thirty hours of formulaic slop until you get to about halfway through Stormblood and suddenly the game starts introducing new mechanics again.
I kept hearing "just get through the MSQ and it gets good" and after finishing the first expansion being bored out of my fucking mind the whole time I started to feel like I'm getting pranked. Then people start saying "Shadowbringers is where it gets REALLY good" and I'm like, okay, time to play another whole expansion of riveting report-to-boring-cutscene gameplay to get there, I guess. And then I just never kept going.
If you found Heavensward really boring then you might like Shadowbringers but you won't find it to be something special and Stormblood would kill you from boredom so it's good that you stopped
Depends on what you are looking for. If you just want to raid it definitely is the case of mining a lot to get to the good stuff. If you want a good story then YMMV since even Heavensward requires you to pay attention to some things in the base game for its story to feel impactful.