Pros/cons of discontinuing a DevOps workflow?
It's not a good idea.

In my experience you'll gain the disadvantages of both while any projected advantages will somehow fail to materialize.

Itemized:


You will lose speed.
IT will comply with their own standard. The new task (for them) will follow the same 'sluggish' template all their work now has. Be prepared they will find it challenging - so even less speed than standard simple actions.
You will fail to offload.
IT will lean on you guys for every single anomaly. You will put in effort to get one guy up to speed -  and the next thing you now you'll be repeating yourself because the following task/problem/day there will be a new guy, again.
Documentation will be required, but it will not help.
Again template behaviour will be that short manuals will fail to catch every anomaly, and thorough texts will not be read for being too long. So any investment here will be a loss, likewise the enormous effort needed to implement improvements to get your tools to 'shrink-wrapped'quality.


Last but not least any problems will reflect on you guys. Tar, tarbrush principle.

If the above sounds cynical, well, I'm afraid I've been there. Repeatedly.

What to do instead?

Go shopping in the IT department, find yourself a useful candidate, and keep this guy 'on loan' to relieve you workload.