The other reason is to find out what a detuned model is capable of. The canonical example is how to make cocaine, which ChatGPT will admonish you for even asking, while llama2-uncensored will happily describe the process which is only really interesting if you're an amateur chemist and want to be Scarface-that-knocks. (the recipe is relatively easy, it's getting access to the raw ingredients that's the hard part, same as with nukes.)

if you accidentally use the word"hack" when trying to get ChatGPT to write some code for you. it'll stop and tell you that hacking is bad, and not a colloquial expression, and refuse to go further.

privacy reasons are another reason to try a local LLM. for the extremely paranoid (justified or not), a local LLM gives users a place to ask questions without the text being fed to a server somewhere for later lawsuit discovery (Google searches are routinely subpoenaed, it's only a matter of time until ChatGPT chats are as well.)

There's an uncensored model for vision available as well. The censored vision models won't play the shallow game of hot or not with you.

There are uncensored image generation models as well, but, ah, those are NSFW and not for polite company. (As well as there's multiple thesis' worth of content on what that'll do to society.)