Hi @hatikumo890 ,
Unfortunately, there is not enough space and time to describe everything, and it always depends on the use case.

Short and sweet:
Currently, Tableau still offers far more features than QuickSight does. But in QuickSight new updates and functions come almost daily. Sometimes you just have to find a workaround or question whether it really makes sense.
Because of the features, Tableau is naturally a bit more complicated to use. But if you assume standard reporting, then both are pretty much the same and easy to learn.
Up to a certain point QuickSight is much cheaper than Tableau with 5$ for Reader and 24$ for Author. At some point, however, Tableau sets in with a core license where the number of users no longer matters. Ultimately, however, we are always talking about list prices here. For example, 100 readers who only call up a dashboard for a few hours a month, QuickSight is significantly cheaper from a license cost perspective.

Otherwise, just ask Google. There are enough pages that go into it.