> and the IBM 390x aka Z/OS platform along with it

The problem with killing the mainframe is that no other platform really exists that can handle the amount of simultanous IO that you can get on a mainframe. Our mainframe easily processes 100m transactions per hour, with room to spare. And keep in mind that those transactions are for the most part synchronous, and will result in multiple SQL transactions per transaction.

Yes, eventual consistency is a thing, but it's a very bad match with the financial world at least, and maybe also military, insurance or medical/health. You can of course also partition the workload, but again, that creates consistency issues when going across shards.

Also, COBOL is far from dead, but it's slowly getting there. I don't know of a single bank that isn't actively working on getting out of the mainframe, though all projections i've seen says that the mainframe and COBOL will be around until at least 2050.

Give that a thought. That's 26 years of writing COBOL. Considering that COBOL programmers are also highly sought after, and usually well paid, one could literally still begin a career as a COBOL programmer today and almost get a full work life worth of it.