I doubt it would improve performance, as C# being a compiled language makes it much more efficient than javascript, and it would also require a 100% rewrite of the game's code (unless you're suggesting to run the game in the backend, which would mean having to host servers for everyone to play from their browsers, which would cost a fortune). Believe me, you'd rather play the game as it is.
Totally agreed, but what I meant by that is that I have a 4 year old Chromebook that runs so slow when I try to use apps in the Linux mode. For me, having a Unity WebGL compile (takes like 2 mins to export and to upload to itch for super easy playing) would be much better for performance and for ease of use. On top of that, people would not have to install stuff :) .