I find it ironic that you blame software when really it is your selection of projects & companies, and you say this out loud.

Your software isn't being used. That sucks. The feeling must suck.

A car maker who builds something for 0 drivers will be sad. A dentist with 0 clients will be sad. Etc, etc.

Go to a big company that has users, and see what that does!

Let's say Series C/D+ -- $100m+ raised.

If you want more users, focus on consumer companies. If you care more about the business making great profits, focus on B2B.