There is still a fair amount of small business dotNET software being written that kind of require windows server but that's mostly targeting standalone desktop

There is still a fair amount of small business dotNET software being written that kind of require windows server but that's mostly targeting standalone desktop application or spreadsheet abuses, but for anything that needs high end servers and advanced storage in order to meet performance Linux is pretty much all of the market right now. There is some niche's in the network space where xBSD plus custom asic's plays a role, due to licensing concerns but more and more vendors are finding a way to do something similar with linux. And as FaaS/CaaS in practice depends on a set of Linux kernel API's those deployments are still Linux clusters underneath all of the obfuscating complexity layers that 90% of people don't actually need, nor benefit from.