You seem to completely miss the point of the GPL.

You're welcome to explain it to me. What benefits do I get from switching from MIT software to GPL one as an end user?

In your view of the world what is an end user?

If we're talking about someone who has received a binary copy of software, then isn't this obvious?

The MIT license permits the distributor to close the source of what they've redistributed, in original or modified form. Potentially depriving the end user of the freedom to view/modify/distribute the source.

Permissive licenses prioritize rights of the software redistributors at the expense of the end users.

https://en.wikipedia.org/wiki/Copyleft#Freedom

The MIT license permits some other developer to fork the source and close it off, but as an end user of this particular software that is under MIT (meaning that source is available, and I can take it and modify it if I need to), how does that affect me?