I think what you're missing is that the number of people doing step 4 has been going downhill steadily since the 2000s. People start open source projects yes, which for 99% of them don't bring in any users and barely get maintained over the long run, but the pool of people willing to contribute to large established projects is so small it is becoming problematic.
Even Wikipedia is having its own editor crisis, where most of the power editors are greying out and barely anyone is stepping up to replace them.
And this is happening exactly because most people, like you, think that the free infrastructure around us is a fait accompli which doesn't require us to personally get involved in their maintenance, and that we can even afford to scare away those that do contribute.