It may look like a crappy Electron app, but Figma has a quite interesting architecture. The browser editor is developed in C++ and cross-compiled to JavaScript with emscripten. The rendering engine looks like its handling HTML, but it's actually rendering their own document format for cross-browser consistency. They have their own CRDT implementation to handle multi-user edits.
I think my biggest question is who cares? What does having an interesting internal architecture have to do with the “its electron though” ideological attack.
It is made to perform much better than your typical electron app would. Saying electron-based == shitty is complete misunderstanding of the technology. Although i dislike Figma as much as the next guy, their app was in many ways very impressive. See Figma's cofounder old articles at https://madebyevan.com/figma/
[0] https://www.madebyevan.com/figma/building-a-professional-des...
[1] https://www.madebyevan.com/figma/
[2] https://www.madebyevan.com/figma/how-figmas-multiplayer-tech...