I am the developer of https://lekh.app When I first experimented with the web assembly, it was kind of magic for me. I had a diagramming app called Lekh Diagram (https://lekh.app/diagram.html). The core logic was written in C++ and is being used in Android and iOS apps. I wanted to make a collaborative web version of the app. Initially I thought I would have to rewrite everything in Javascript. But when I first tried to compile all the c++ code into web assembly, it was around 4M of web assembly. And the performance was awesome. I was pretty satisfied with 4M. Then I started developing the Lekh Board (web version of the diagramming app). Later in the development phase, I realized there is a flag which I can pass to reduce the size further. Then I got the web assembly size ~1M.