For most people, [open source] is a hobby. It might be a hobby that people would love to be paid for, but then golfers or skiers would probably say the same too
Just keep comparing projects which form of basis of billion dollar codebases to people doing bougie sports. That’ll make your point for sure
A lot of tech companies that are only profitable because of this free labor would go out of business, but the main monopoly companies would still exist, they would just have to spend more money on development and less on stock buybacks