Earlier quoted context omitted.
Sure. But it still takes some time until the interactive part works. And it doesn't solve connectivity issues a SPA can easily handle.
SPA = single page application. You can make one entirely in Blazor and can host it on any static file host. Are you talking about Javascript specifically?
Blazor Server: On a broken/poor connection there is no interactivity anymore
Blazor WASM (=SPA): Keeps working when connection is lost, but everything is sooo slow
classic SPA: Keeps working with lost connection and is fast.