Totally agree! This is an orthogonal issue, and I tried to start a discussion on that some time ago on slack. Not much extra compute is needed to run these checks rarely, from time to time — and even this would catch lots of issues. What’s missing is infrastructure + buyin from packages.
I tried playing with this kind of compat testing for my packages, but buyin is critical — doesn’t make sense to do that for a small subset. See oldnew_compat.yml · GitHub for a github action example that tests for either oldest/newest versions of each dep, or for all versions from oldest to newest.