Microsoft insisted on introducing a bunch of breaking changes into .NET Core (and all future .NET versions), making 4.8 a "dead end" in which many enterprise customers of mine have become stuck.

ASP.NET Web Forms sites are especially stuck, and on top of that I have customers that have developed Web Forms sites in VB.NET! Luckily there are some good bulk-conversion tools available now, but still, there is no smooth upgrade path for a lot of popular systems.

Similarly, Windows Communication Foundation, Workflow Foundation, and a bunch of other popular libraries or frameworks are dead in the water. SAP Crystal Reports is surprisingly common, but doesn't even have an official NuGet package!