There’s many things named simplex… Doesn’t have to relate to Herpes: https://en.m.wikipedia.org/wiki/Simplex_(disambiguation)

When a piece of road is properly connected, there’s very little reason for others to go and disconnect it again.

There’s also an approval system, so changes made has to be reviewed by others, and you have comments to explain why and what you did.

Disconnected roads like the one OP mentions happens by accident, not by intention.

All the fixes I have put into OpenStreetMaps has stayed there.

I’ve seen that happen in both Google Maps and OpenStreetMaps…

But the nice thing about something crowdsourced like OpenStreetMaps, is that I can just hop on their editor and fix the street that is broken.