The new asp.net took a lot of good concepts from the node ecosystem and feels really modern. It has a lot of batteries included. I think .net is an awesome platform to build backends. I wouldn’t use it for frontend though. Razor and Blazor never really convinced me.
Blazer Server is perfect for internal applications and dashboards though. It's just so easy to use, especially if you plug in any of the community made component libraries like MudBlazor. I had pure backend devs actually happily make frontend for once. It's essentially Phoenix's LiveView but in C# and that uses already proven SignalR.
For me Blazor is a mess. It’s component system is even worse then Angular, a complete OOP-mess. Yes it’s easy to use, but some things don’t work and it takes ages to find out why.