> I wonder why others don't work for free too?

You need to explain the billions of lines of open source code.

> It's not possible to prove that something can't be done.

This is just sophistry. Many "business models" are being tried, granted none seems to be failproof but it suggests there is a space to explore.

We are talking about a process that is barely two decades old. The familiarity and safety of paid work with fiat money, contracts, private investment and all that, its all based on inventions that came about to solve similar frictions in the past.

Most by volume perhaps but not the projects actually being used.

Those belong into "....outside paying jobs", given that they are powered by big corp money with strings attached.

coders are both artists and artisans, sometimes it’s just beautiful, sometimes it can generate money