I think that distributions patching software is especially problematic -- whether you consider it a symptom or a cause of fragmentation.
Here's two examples of how distros patching software has been helpful for me.
1) SquirrelMail (abandoned) patched to work with PHP 7.3 thanks to FreeBSD contribs
2) Abiword patch builds in the AUR that fix a broken default install.
I'd rather see that useful changes are merged upstream, or projects are forked. If this had happened, you wouldn't even need to patch, and this would save an enormous amount of manpower that is wasted on trivialities.