Anything with canvas, or a very interactive experience I think Blazor is a bad fit for. I'd do just straight JavaScript or typescript.

But so much of the world is user clicks a button, run server side code, update html, and blazor is an amazing fit for that.

Like I'd never build a Google sheets, Microsoft word, or outlook replacement in Blazor.

But I'd totally build a hub spot, Salesforce, Facebook, reddit or hacker news clone with it.