I suppose two issues are at play: centralized OSS project stewardship that alters direction every 3-5 years to meet evolving org goals, and people building cons

I suppose two issues are at play: centralized OSS project stewardship that alters direction every 3-5 years to meet evolving org goals, and people building consulting careers on top of OSS projects that are strongly aligned with org goals (extreme case for impacted users). At least some of your million dev userbase comprises of consultancy shops, contributing in part to your popularity by building products for their clients, but also making a buck with low effort on the underlying tech. They end up stitching codebases using unusual practices to meet deadlines that often blow up when a migration is upon them. Angular had a migration tool called ngUpgrade that was painful in the wild. All I'm saying is, these tradeoffs have now surfaced and crystallized.