Comment by The5thElephant

Figma on desktop is an Electron app I believe. Figma chose to build a custom webGL rendering engine for their design canvas, so the core issue is that technical decision early on (probably allowed for some better performance and multiplayer back then). Figma is stuck with wanting to control their rendering and allow for non-product stuff like Figjam or the new Draw tools, but it will inherently hold them back from providing a really good design/dev handoff and always will hold designers back because it doesn't use CSS web rendering.