Web development is entering to a totally new phase with WebAssembly coming in. With WebAssembly it is possible to run desktop like applications inside a browser — with almost the same performance!
Imagine using the popular AutoCAD software on a browser. It is possible with WebAssembly.
The below video was recently presented at Google I/O '19. The first half is interesting and will give you an idea of the possible use-cases of WebAssembly in web applications. Because WebAssembly is so powerful, there are high chances that you will need to learn it in the coming years. It may be time for web developers to gear up for C, C++ coding too.