You don't have typescript's typechecking for templates.

You don't have higher-order components or first class components. Scoped slots are almost there, but not quite.

Also, "scoped slots" show that vue's simplicity is a bit of an illusion. There is a lot of reinventing the wheel happening underneath to get templates to the basic level of modularity / encapsulation / features of plain old JS.

It was similar with Angular. "Look how simple it is!" - yeah, until you actually need to build something serious with it... then you need to learn 3 times as much as React and all its tooling.

Here is an exercise: Write a spinner component in vue that renders either a spinner, an error message, or any other component (must be passed to the spinner component as a parameter) to which you can pass the data of the fulfilled promise.

Here is a react implementation:

https://jsfiddle.net/mm145xkj/

You just write a component where you pass two props: a promise to monitor, and a function that will take the data of the fulfulled promise and use it to render anything.

How do you do that in Vue? Is it simpler than the React implementation?