>How can anyone compete against a trillion dollar company that's fine with subsidizing an unprofitable business line?

It sounds like impossible, but it's not always. Sometimes large companies loose the focus and become slow. There can be multiple competing products and teams are prevented from building the best product in order to not interfere more profitable business. Microsoft for example has both GitHub and Azure DevOps.

One example of how the infinite resources do not always help. Year ago GitHub decided not proceed with adding support for Python packages in GitHub packages. "This is no longer planned due to a change in our strategic priorities and the allocation of our resources towards higher-priority initiatives." [1]

[1] https://github.com/github/roadmap/issues/94#issuecomment-158...