I'm curious what the missing features are in Figma from a designers perspective. You've mentioned the paywalled variables, what else? (I haven't been a product engineer in years, and have barely touched Figma in the last ~5 years)
- Clunky component and variable system; inadequate for more complex stuff with lots of parameters.
- Can't set connectors on Design files (used for documenting the navigation flow between different pages of an app).
- You can set connectors on FigJam files, but if you want to bring your components from Design files then you can't keep the instances synchronised to the component definition. And you can't attach the connector endpoint to some element inside the Design component. It's essentially just an image export of the Design component.
- Prototyping is very clunky and trying to build a flow that has elements reacting to interactions on other distinct elements is either variable hell or downright impossible.
Those are just off the top of my mind. I'm always finding threads from 5 years ago on their community forums with loads of people on the same boat and no activity from Figma side.