The full use case includes quantisation, which the repo points out uses a large amount of system RAM. Of course that’s not required if you skip that step.
Judging from downloads of the 4bit file and how many people I've seen post about quantizing it themselves, around 99% of people are just downloading the pre-quantized files.
I would not personally call compilation of software part of its "use case." It's use case is text generation.
Quantisation is a once off process. I suspect most people who don't have access to a machine with enough RAM and don't want to use the pre-quantized version can afford the $20 to hire a big cloud server for an day.
Or it is probably possible to make it work slowly using a swapfile on Linux.
I would not personally call compilation of software part of its "use case." It's use case is text generation.