I dont think you have checked Blazor runtime libraries size. Last time I tried, it downloaded 5MB wasm files to the client in a simple hello-world screen.
Ultimately, I don't think 5MB blobs are all that bad for web applications that need the enormous complexity these libraries provide. Classic Django/Symphony/Spring Boot with some CSS animations and Javascript glue can work perfectly for the smaller apps. For things that aren't applications, you shouldn't need any framework at all, websites can/should just be static files to make everyone's lives easier.
The cases where this makes sense are probably internal enterprise applications or advanced tools.
For everyone else, there is this: https://whatdoesmysitecost.com/#gniCost (or at least it was a curious reference, before the pricing figures seemed to kind of break in other tabs; though this might as well be considered, not just site load times, or battery life implications)