I admire this, tried it and it's very good. I even had a feature suggestion accepted for development.
But for some reason, unlike most tools I use, I don't actually care or have an issue with Figma not being open source.
Therefore: Figma works well, has a vibrant plugin ecosystem, lots of 3rd party design assets, can be used on any platform and in 4 years I've never needed to pay for it....
So tbh I can't find the motivation to jump ship to something else.