You almost had me there

Not really sure what you mean. I wasn't trying to get you at all, it's completely sincere.

where's the story in it, is it a good one in the original?

It's an RTS, so not really a story-based genre. The community is mainly based around competitive multiplayer and fun casual multiplayer—either against AI or in vision scenarios. But the campaigns have generally been good, albeit very different from game to game.

AoE1 campaigns had almost no story to them, just a brief explanation of a period of time and set-up for the mission.

AoE2 campaigns focus on a particular notable figure from their respective culture, with voiced introductions and wrap-ups to each mission providing characterisation in addition to explaining the set-up.

Age of Mythology is in my opinion the best, as they took various myths from the 3 mythologies the game is based on and wove them into their own unique story with in-game cinematics and voice acting.

AoE3 does much the same, but it came across weird because of the ostensibly historical nature of the game not meshing so well with an entirely fictional story.

AoE4 came out very recently and is similar in scope to AoE1, jumping across centuries showing snapshots of a civilisation's rise and fall. But it has incredible production value with narrated introductions superimposing historical details over real-life modern footage of the relevant sites, in addition to brief in-game narration of the type AoE2 also shares.

What will AoE Mobile's campaigns be like? No idea. It was first announced in October 2022 at AoE4's 1 year anniversary along side the Age of Mythology definitive edition game, but later this month will be the first time we've gotten anything official about it since then.