I have been programming with Blazor for over 2 years now, starting with the previews. It's incredibly easy to program and if you use a code-behind file for each component to separate the code from the markup, everything is tidy and pretty, unlike React or Knockout. I switched the project to Blazor WebAssembly in May. It's fast. Judging by the number of job postings requiring Blazor, it doesn't look like anyone is using it much already, but I'm hoping this changes in the next few months. One good thing to note about Blazor is that it doesn't require node.js, etc., so the solution footprint is much, much smaller. And you don't need to wait endlessly when you have to rebuild the entire solution. I'm sold.