Unlike most of you, I don't regularly call in for retention offers - I only call in when I've decided the card doesn't make sense for me anymore given the benefits. I have a business and personal Platinum and there's just no reason for me to keep both this year, since most airlines are no longer charging change fees (I never buy basic economy) and I don't check baggage, etc., I don't use the 35% points thing since I keep my points around for short-haul Delta (often a good deal unlike business class or international).
Called in, explained, she said due to my loyalty and having multiple cards with them, they were able to offer me a full statement credit for the annual fee. Which is great, so I used it and will keep the card for one more year.
Mentioned to the CSR that there aren't many benefits that are really unique to the Business Platinum anymore and she said she couldn't tell me details but there were good things coming in a few months. Take that for what it's worth...