Unless I'm misunderstanding your point, your HTTP server from 35 years ago is still working today without any maintenance? Does that mean no security patching and no updates for bugfixes? or does "no maintenance" means something else I'm missing? I find it difficult to discuss these topics when comments like these pretend that you can leave your system exposed on the internet for years without any maintenance.

If we're talking applications that don't actively listen on the internet that's fine, and I would agree that we should have complete software that just works. But a webserver, unless it's for personal/home use, it's on the internet and I don't see how it could work for 35 years without any update/change