One of the key things RedHat sells is "your code doesn't need to change for X years" - but a side effect of this is you suddenly have a BUNCH of changes that need to be made every X years as new distributions come out.

Even though Microsoft deprecates versions of Windows, they often keep supporting the APIs used for insanely long periods of time. Open Source software doesn't really have the incentive to do this unless "forced" by leadership or a standards body (and even that isn't entirely well enforced, how deviated from Posix are we now).

Java may be similar to a cross between these - as old versions of the JDK continue to be supported and developed, but I assume there's money flowing somewhere to do so.