I used to work in IT in a large corporation back in the days. Amount of work necessary to procure software was so staggering, that any alternative "creative solution" would be much more preferable. And the worst thing is that the cheap software was the one that suffered most. The gazillion-dollar CISCO upgrade was no problem, it's already gazillion dollars. But to get $10 email shareware license one would spend many work-hours of many people, so who's gonna do it.
Took a meeting once with a customer who had been evaluating our product, which was not OSS. It was a nice meeting, they loved our product and seemingly they would purchase. Awkwardly the guy said their CEO had a rule: they could only use OSS. Their own product was not OSS.
Yes I am having this with trying to get some Neurodiversity software on my laptop, lots of people keen to help, government even refunds the cost, but setting up a new supplier is hard work, and then security approval too.
From the accounting perspective, it's likely to prevent accounts payable fraud.