I noticed that I did not have the Bulk Edit option on one of my selling ID's, but knew it was present on another so it must be an isolated thing. After a little digging, I realized it was because eBay had opted me into "business policies" which is also responsible for all of the annoying shipping profiles. By opting out, the option for "handling time" has reappeared in bulk edit AND I have original shipping options instead of being forced to choose one of a thousand shipping profiles.
When researching, I found a lot of people had the same issue over the years and I didn't see any resolution posted (forgive me if I missed it), so I thought I'd share. Here's how I did it:
https://www.bizpolicy.ebay.com/businesspolicy/manage
Choose "opt out" in small print toward the top right.
And you can read more about them here to see what you're opting In or Out of :https://www.ebay.com/help/policies/business-policy/business-policies?id=4212
Hope that helps! 🙂