I would suggest looking into supporting Blazor client-side programming with ServiceStack, at least a C# client that works with the ServiceStack cli (https://docs.servicestack.net/csharp-client).
A Community ServiceStack + Blazor template that supports .NET 5.0 is available:
Client Template for Blazor WebAssembly client-side.
Johan Mulder commented
Starter template with Blazor authentication/authorization integrated into SS. Also a working SS Httpclient + SSE example.
George Hemmings commented
I'm also hoping for Blazor Server support. This could be just a SS ComponentBase with templates for integration with SS Auth.