That's assuming downstream is even still around to adopt the new version. There are plenty of simpler tools which are "done" - itch scratched - and the author has long since moved onto new things. Duct-taping the bitrot inflicted by toolkit churn is something that requires resources - if nothing else it consumes time and energy that people could otherwise be spending on current interests and projects. That's where the "open-source means everything's free" mindset can be a problem, since it's just assumed the authors will step up and do work made necessary by the decisions of others, with no remuneration or consideration.