Looking at the current CNCF landscape, majority of the graduated projects have huge backing from single corps - promoted with the open source labelling.
i.e. argo by Intuit, Cilium by Cisco, SPIFFE/SPIRE by VMware/HPE
The main conundrum is the sheer cost of maintaining dotnet and its surrounding infrastructure, and the teams to keep it moving forward fast.
But should unthinkable happen, it is MIT licensed so one or more companies can just carry on with their fork or maybe even transfer existing org/repos to some newly formed foundation.
Now I understand there's little chance microsoft kills it, but I would assume people would have thought that of their perpetual licenses or plans for VMWare, they maybe thought they're not going to kill their clients, they're not going to kill sales partners because XYY, the truth is, there are good technologies very dependent on corporations deciding their directions, but those technologies aren't that level better than open ones to justify the risk
No, it doesn’t seem to be the case. And C# mostly does not need multiple back-end frameworks because the out of box option (which is just a part of dotnet foundation ecosystem of repositories) provides the best performance out of all alternatives like Servicestack. This does not mean someone won’t implement another one in the future to sacrifice even more ASP.NET Core style features to minimize the overhead even further or to address specialized scenarios.