Vast majority of time is used up on handling useful but not fully correct data.
I am not aware of any datasets that are high quality, on a compatible license, including data of interest to OSM and existing for longer than a year - that would not be imported already.
There are more people interested in making imports than high quality datasets on a compatible licenses, this is not the bottleneck.
- import (adding object to database) - for example https://budynki.openstreetmap.org.pl/ is used by OSM community in Poland to import official address and building data after review (sadly, quality makes necessary to review data but still saves time overall)
- using for mapping (for example Bing aerial, Strava heatmap, aerial imagery released by many governments is also available on a compatible license)
- linking (for example many OSM objects link Wikipedia articles about them or their official website)
- used to find places for mapping (if Google starts showing new road I am not allowed to copy it into OSM - both due to licensing and low quality of Google data. But I can select this place for the next bicycle trip and map everything there as I survey this area)
Not sure how it matches general terminology, OSM has some slang/terms which is sometime incompatible or unknown elsewhere.
Ideally, governments would simply pay OSM people to do it on their own, but eh, we know this can never happen, and even if it did, greedy people might be tempted by that kind of money and would go into the OSM community just for that.