Yes, had to move even before started building the more advanced features like hosting. There were some bugs with the JS number type causing weird issues with emscripten. It's been a while so I don't remember the details.

Additionally, and perhaps counter-intuitively the server-side solution was better for folks in areas with bad internet and computers. Downloading 10mb of JavaScript is a lot for some people and sometimes their computers would run out of memory parsing the JS.