I'm not against dungeons or side quests but they have to be lean and fun and the remake strikes the perfect balance.
Nah, dungeons should be labyrinths that whittle down your resources to make you pause and think. RPGs are thinking games. Narrative is important but should never take over the bread and butter of resource management and exploration. Phoenix Cave is an hour long dungeon that takes full advantage of the games systems. Not every dungeon should be a labyrinth like the Tower of Zot and some should be straight forward, but when it's on it's gotta be
on.
The only reason FFX is successful in what it did (linear with light dungeons) is because of the plot. They're on the way to a predetermined destination and the plot is the focus. It has side dungeons that are pretty good like Omega Ruins and Yojimbo's cave. So it works. But that style of RPG, which is linear and gated, is very limited. Final Fantasy IV is almost as linear as X already. It's usually from A to B and the party is almost always predetermined. This makes IV boring to replay, because it's mostly a traintrack, has zero customization, almost zero options, zero choice. FFX is the same. It fucking sucks replaying it. Tidus kills dogs, Wakka kills birds;etc. Train track to the next cutscene.

Only until FFX International with its added Advanced Sphere Grid which allows the player a semblance of choice did FFX gain any inherent replay value beyond its fantastic story.