Blazor is not intended for websites, it is intended for enterprise, intranet CRUD applications with interactive forms, tables, etc. Especially if you already have .Net on the backend. I just finished one such application on Blazor Server and it works great. Programming was easy having previous experience with Angular.
Edit: And the most important advantage, next to productivity, is maintainability, without the entire JS/TS/Node toolkit.
Edit: And the most important advantage, next to productivity, is maintainability, without the entire JS/TS/Node toolkit.