It's the market distortion created by people who work for free and expect to get stuff for free
It seems like OSS is more and more bigcorp making money anyway so probably that perception will keep shifting until we're back to normal conditions and OSS developers will be able to earn a salary from their work.
Who said anything about free? Have you used Rive Designer? It's $39 per month for a basic animation DCC tool, which is based online and your files are locked away so you can only alter them if you keep paying perpetually. For a solo developer doing basic animation now and then, the price is absolutely insane for the stuff you get out of it.
It seems like OSS is more and more bigcorp making money anyway so probably that perception will keep shifting until we're back to normal conditions and OSS developers will be able to earn a salary from their work.