The download size does make it hard to use for a "public" site, like a webshop. But it is a different story for an application, like an intranet solution or app like Figma. A first time download of a few MB's is not a problem, as you regularly use it. Like a desktop application.

It is the first time you can develop a full stack application (client and backend) in one language in one debugging session. For C# that was possible with Silverlight.

Small companies (like mine) that deliver applications and have full stack engineers can have some amazing productivity!

So for my needs I'm really excited with something like Blazor, and this was only the first release.

I understand the appeal for .net devs.

I just don't think it's a good idea in general.

For every person whining about 60k JS there are 10 creating 10MB web app.