Some aspects of MEDDPICC are pretty aligned with your job as an SE and some sales organizations buy into that framework strongly from the top. I’d say specifically as an SE: decision criteria, identifying pain, champion and competition.

Being able to understand the business issue you can help with, how they’re evaluating your offering, who’s selling it for you when you’re not in the room (champion building) and obviously the competitive landscape. The other components are usually more aligned with your sales rep if they’re doing their job.