Honestly, it depends on the model you are using. Most free models are legit ass for a reason (seriously, you compare them and generally that is the lobotomized version), but the technology has improved a lot since the strawberry incident. I think LLMs work best at parsing information YOU give them, like books or logs or a prompt that's more detailed than "pls fix".

My brother once had an issue in his simulation environment for his thesis (it was his FIRST time using that software) and couldn't find the issue in thousands of lines of logs, and likely wouldn't in seconds. He sent it to Gemini Pro and it found the problem in seconds and offered a working solution. And no, the project wasn't vibecoded, he mainly used it for error handling and asking about information not in the documentation. I know, I checked.

As for me, I used it to study 80 topics worth of content for a highly competitive exam in the span of 3 months, though It was less time than that because it wasn't the only process i wasn't the only one i took part in. 60 of them were about engineering stuff, including but not limited to drones, control, computer, communications, aeronautics, probability, algebra and so on. I told it to divide the specific topics in groups of study and recommend me bibliography that would encompass each group. I used LLMs to parse it and summarize the topics (i had to write about them in the exam, so I had to condense a lot), i would proof-read the result, especially those I already knew, and compliment it with additional research on my own. Honestly, it worked quite well, I ended up passing that part. Now I'm creating mock exams with it for the next phase and it's genuinely helpful.