As a tl;dr there is very little reason to pay for Tabnine. Copilot is far superior in the realm of paid products, and Codeium is comparable to Copilot.
What exactly is the business model though? It's always a red flag when "privacy respecting" and "free" are bundled together. I definitely _want_ to pay something for that type of service.
We actually worked out the math - we don't use any external APIs like OpenAI (use our own models) so those costs aren't prohibitive, and we have a bunch of experience as a team building scalable ML systems, so we have driven down the serving costs by a lot.