The point is that if you convert away from COBOL to a more modern language, you can also move away from Z-series hardware to commodity x86 and ARM servers. That's why this announcement affected IBM's share price.
IEEE 754-2008 defines decimal floating point arithmetic that is compatible with COBOL and is usually implemented using the Intel Decimal Floating Point Math Library on commodity hardware.
For a typical core banking ledger application, the performance cost of a software implementation of DFP (vs. having DFP hardware instructions) is pretty low, and greatly outweighed by the benefits of being able to use commodity hardware and more maintainable languages.
IEEE 754-2008 defines decimal floating point arithmetic that is compatible with COBOL and is usually implemented using the Intel Decimal Floating Point Math Library on commodity hardware.
For a typical core banking ledger application, the performance cost of a software implementation of DFP (vs. having DFP hardware instructions) is pretty low, and greatly outweighed by the benefits of being able to use commodity hardware and more maintainable languages.