Although their hardware engineering group certainly isn’t using MAC OS, I can tell you that with a high degree of certainty.
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1) What do they run for their OS?
2) What application do they run on that OS?
3) Why can’t MacOS run that application, if that’s what you said.
Sorry, I missed your reply. Companies who design complex ICs, FPGAs, ASICs, and PCBs are using at least some tools from Synopsys, Cadence, Magma Design Automation and Mentor Graphics. This means Windows for some things and Linux for others. In some cases, these tools can run the customer’s choice of Linux or Windows, but many are one-OS tools.
Software tools in this industry don’t run on MAC OS, and the complexity of the tools and risk of a mistake in manufacturing means engineers need to run them in the approved OS build only, not a “compatible” one.
For example, I’ve seen a complex IC-design application that had issues in an unsupported, but by all descriptions perfectly compatible, linux release package but ran fine in the officially supported linux package.
Just answering you for trivia’s sake. Apple can forever exist profitably and successfully despite not being used on an engineer’s desk.