If Verizon offers $800 trade-in, and ATT zero, why shouldn’t I switch

Bye bye... 

This is a customer populated forum. If you're looking for two AT&T to sweeten the pot to keep you why should they? You obviously have other choices and your willingness to switch says you're not loyal, at least not unless you're bribed.  That's not loyalty 

The trade in deal requires that the trade in phone to be valued at $95 or higher to get the full $800 credit. A cracked screen would make that unlikely but the final evaluation is done by the third party that receives the trade in, not any store. So, though it is unlikely that trade in would get the full trade in credit, it’s possible. I’m pretty sure Verizon’s trade in deal works the same way, so don’t be surprised if you don’t get that full $800 from Verizon either.

@sandblaster

Verizon has been running second fiddle to AT&T's offer for a while and has been losing  ground to T-Mobile as well.

Their offer for the past full year has included damaged phones. Similar to AT&T's Samsung offer, Verizon is offering the damaged phone trade in on the iPhone 14.

    I don't know about you but I smell a whiff of desperation. 🦨

Sandblaster - thanks for the info re third party evaluation, that makes sense. 
Formerly- I’ve been an ATT customer for 10 years. But blind loyalty to a corporation is just silly.  But thanks for the comment. Cheers!