Handling larceny, and other crime is less about realism than about development cost. Handling crime well is quite costly, so many games have a fairly simple system.
In BG1 you might hear "I am the flaming fist", or in BG2 "For the glory of Amn", and you immediaely know that there is going to be no depth to the ensuing interaction.
If BG3 were specifically about crime, I would want it handled with some detail, but as thief skills are almost an afterthought in modern D&D, I don't really expect much complexity to be introduced.
