Blazor performance

I would like to start using Blazor, despite the fact that it is still at the alpha level.

As I understand it, Blazor uses WebAssembly to compile C# on the client side.

And I have these questions:

Does this approach run faster than, for example, React / Vue.js, compiled in JavaScript?

Is it true that the browser will need to download the WebAssembly library every time the page loads?

On the Internet there aren't any comparisons of the performance of popular JavaScript frameworks. So I would like to know the theoretical performance of the new framework from Microsoft.