Just on Southee, I don't love his captaincy or his recent bowling form either and I agree it's problematic if the captaincy is keeping him in the side.
However, our run under his captaincy has been no worse than our performances under a combination of KW and Latham from WTC2021 until Southee was installed as captain. Actually, for me 2022 (diabolical losses to South Africa and Bangladesh at home and then an unparalleled series of 4th innings chokes in England) was worse than Southee's tenure, and less explicable given we still had at least partially KJ, Boult, Good Conway, Good Blundell etc.
Today's loss honestly feels like the nadir for me of 2.5 years worth of bad cricket, dumb cricket, and gutless choking, but tbf 2022 was worse and under Southee we've had some good moments too whether by good luck or good management. I think the rot goes a lot deeper than Southee, a sort of weak-minded complacent obliviousness that I don't know how to fix. Like, we've always found ways to lose games we shouldn't, that's NZ cricket, but we're really doing it with a sort of post-ironic panache these days.