OSM is mostly volunteers, and if no one has happened by on your street in the last 6 years, then no one has noticed to update the map.

> I actually found StreetComplete a few days ago and have started fixing issues, at least for my neighborhood.

This is the expected outcome, locals fixing local issues. Given a sufficient amount of that, and you have a better map than googles offering. Of course, as you discovered, if no one is around to make the fixes, the data also goes stale.

And OSM is the only map that shows the new roundabouts near my house. I just put them in yesterday after riding my bicycle around them several times to get a track.

We are OSM! If it has shortcomings, we've no one to blame but ourselves.