If CUDA were a startup, it could be a VC-powered unicorn (not sure about the deserving, but they'd have decent shot at monetization). Unfortunately, my tool knowledge is not broad due to the limitations of the few tech-stacks I'm familiar with.

Honorable mentions: R and Rust, maybe? But I don't see how they'd make the money back (which perhaps is the challenge Docker is running into)

edit: Also SQLite!

2nd edit: I completely misunderstood your question, I think. The answer is "none" - there are no tools that need to be unicorns, at least for those that are downloaded and can be run locally. Those that I listed could be.