Kingdom Come: Deliverance deliberately doesn’t allow you to save the game whenever you feel like it, insisting that you either buy or brew a bottle of something called Saviour Schnapps first.
The lack of quicksave was one the criticisms in Edwin’s Kingdom Come review.
While the game does autosave on occasion, it doesn’t do so when you exit out, so it’s understandable that one of the very first Kingdom Come mods is one that does away with this punishing save restriction.
There have been reports that, with the mod installed, people have been unable to save at all after their 300th save.