Thank you very much for asking this question and triggering the discussion!
I have nothing to add to what's already been said here, I was happy to see your question cause it's something that I keep thinking a lot about. I am not quite a fresh graduate as I have about 6 years of experience, but I do work in a field (embedded systems for MedTech) where mentoring could be quite beneficial in my opinion. I was particularly bothered by the lack of mentoring in my initial jobs and my recent job change has been largely motivated by this. In my current job, I now have engineers with a decade or more experience than me and it helped me in the following ways:
1. The most obvious benefit has been the fact that I can now reach out to my seniors in case I get stuck debugging something and I see no way out.
2. Another benefit, that's quite underrated IMO, is that having experienced engineers around opens up opportunities to observe them closely at their craft and question them (to understand why) about their design choices etc.
3. In my case, there is a strong motivation to compare my skill set with theirs and critically assess where my shortcomings/areas to improve are.
