So now that Figma will be owned by Wall Street, it will only get considerably worse from here. It is now time consider and find and fund open source alternatives.
I know of excalidraw and perhaps penpot are there anymore?
And how would that happen? They already have the product, which can be sold in huge numbers without really needing to scale operations. Are you suggesting they need cash to rewrite or improve the product?
At my company we use Miro a ton. It doesn't have the design tools, just the white boarding and diagramming, so its Figma counterpart is FigJam. But the realtime collaboration features are just as good, and sometimes better. They have a decent desktop Electron app that wraps it, too.
I know of excalidraw and perhaps penpot are there anymore?