I think the idea that dropping compatibility helps forward improvement is oversold. To quote “Things you should never do” https://www.joelonsoftware.com/2000/04/06/things-you-should-never-do-part-i/ . There’s no guarantee that the new version will be any better than the old version, because the people who actually learned things from the old version have moved on, conversely, the old version has all the cruft, which are otherwise known as “fixes” and which guarantee that it works reliably in all kinds of environments, something your new fancy version won’t have until it too becomes old.
I think the idea that dropping compatibility helps forward improvement is oversold. To quote “Things you should never do” https://www.joelonsoftware.com/2000/04/06/things-you-should-never-do-part-i/ . There’s no guarantee that the new version will be any better than the old version, because the people who actually learned things from the old version have moved on, conversely, the old version has all the cruft, which are otherwise known as “fixes” and which guarantee that it works reliably in all kinds of environments, something your new fancy version won’t have until it too becomes old.