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.

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.

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.