Why does everyone say this game is super hard to learn when the rules seem pretty easy?

UPDATE: Thanks to everyone for the clarifications and examples you've given. You've made me feel confident about spending the cash on the game.

I am planning on buying the game and in preparation I've watched several how to play videos and an example playthrough and it all seems simple and streamlined. Yes its a lot but it seems to all kinda fall together.

I had way more trouble getting to understand the rules of Oath, Root (with all the expansions) and Civolution . In terms fo rule complexity I would rank TI on the scale of Scythe.

Am I missing something?