I started off with asp.net mvc today. It's confusing to see why asp.net mvc apps make use of JS programs or jquery files, bootstrap, or Angular. Can't we get all of those functionalities that they provide with asp.net only, like in cshtml view files?

Also, as the title explains, why is asp.net even used when we can build web sites and web apps just as well with all those other technologies alone.

I think my understanding of asp.net or .net itself is weak.