Comment by a_bonobo
My experience is that the 0% interest on credit time for large companies enabled open source to thrive: open source maintainers were flush with cash and time. Large companies with ample cash let their staff do anything to keep them happy (and away from their competitors!), including allocated time for OSS contributions.
Now that 0% interest has ended 'regular' people like me are not flush with cash. Any time I have I need to spend on activities that will bring in money. Why would I waste that on open source?
(Another aspect is the McKinsey-ification of the work place in the last ~10 years or so. Managers are making decisions in tech now, not tech people. all my life I was told that OSS contributions will look great on my CV. So far nobody who has made a decision to hire me has had the background, interest, or knowledge to judge, or even care, for my OSS contributions.)