Programming

I think that one reason why the proportion of open source code grows is software quality:

Companies would love to own all their code. So, when they employ people who work on proprietary code, the amount of proprietary code should grow, shouldn't it?

Except that companies have mostly very short-term goals. And this affects quality: A lot of proprietary code has quite shit quality and is not really maintainable. Which has the effect that either the project dies, or becomes very slow to develop further, because of tons of technical debt.

So, the company eventually will resort to rewrite that project. But that is like walking on a threadmill; it always takes a long time until a rewrite of an old project matches the predecessor projects features and stability. And the current GenAI craze will only make that threadmill rotate faster...

FOSS projects do not have this obsessive constraint on short-term returns, so they often have better quality. Which makes it more likely that these projects live and prosper a bit longer. The short-term difference might not be even large - but the process goes year for year, round for round, and it becomes an evolutionary advantage.

In the end, everyone uses that Finnish students former hobby kernel project, and nobody uses Windows 95 - or wants to use its shitty successors.

(And this is why I also think that Guix will win in the long term: The capability to re-produce all components of a program or system from freely available source is, in the long run, an overwhelming evolutionary advantage.)