Its not be most C-level execs are these companies can present it as IT evolution and progress. Balance sheets look different because accounting has costs in different places. It all looks good.

Well your also hardware locked. The last time I worked on a mainframe (about a decade), 8 mb of RAM was $1000, a network card was $800. Commodity hardware around the same time 8mb was probably $50 and a network card even a good one was most $100.

You're paying a premium for both the hardware and the lack of develops knowing EBSIDIC, JCL, Cobol, etc..

Actually, from what I remember of Oracle, that might be very similar. I remember having to pay license fees per core.

The lock-in is less severe on AWS/Azure/Oracle/Google.

I'm assuming FedEx wants to be in the package delivery business, not the owning compute hardware, datacenter, cooling and power business.