and i should add that this constraint is one of the reasons why some products get discontinued. right now, I'm dealing with migrating a dependency that has some breaking changes in an old section of my codebase that nobody has touched in years. I have to change it, because the dependency is changing, and I cannot continue to depend on the earlier version.

Happily, it is a simple enough update (and frequently these changes are automated by whomever is actually changing the library). But when this is something that needs extensive reworking, the project might get turned down instead.