The software side is funded by how big the market is for Apple products, which is accumulated over the year, not how well the hardware sales is for a given period. Just because hardware sales for 2021 was slow, for example, doesn’t mean software and services sales are slow accordingly.
> It would be unusual for any long-established business to be ramping up hiring at the same time that supply constraints are diminishing revenue.
This is not unusual at all. When hardware sales is down company often want to compensate by increasing software sales, that likely means uptick in hiring. In fact that’s one of the strength of Apple. They can weather worsen market conditions thanks to their diversified product and services portfolio.