Organizations deliver value by fulfilling responsibilities
A business does not deliver value by running software. It delivers value by fulfilling responsibilities — to customers, to partners, to staff. Software is one way of fulfilling those responsibilities. So are people. So are partners. So are manual processes.
This distinction matters because it changes where architecture starts. Architecture that starts from the business responsibility — what are we actually committing to do? — produces systems that reflect how the business works. Architecture that starts from the software produces systems that reflect how the software was built.
The operating model comes first. Technology is how you fulfill it.