It's not. You can literally have a simple "hello world" app in a handful of lines or code if you want.

I have to wonder if you actually use ASP.NET Core yourself, because ASP.NET Core 3 is, IMO, fantastic. ASP.NET used to be a bit clunky, and lacking in extensibility points, and a lot of people used alternatives like Nancy instead. Nancy officially stopped development around a year back, largely because dotnet devs just don't need it anymore. I was a long-time Nancy fan myself, ASP.NET Core 3 has all the best bits and more.

And you don't need to stick with the typical paradigm on controllers in one folder, views in another etc - feature folders work great. Hell, you don't even really need to use controllers, if Razor Pages are your thing.

it smokes Spring in benchmarks, often by a factor of 10x or more, and on plaintext it's 50x faster than spring and even with the fastest Rust/C++ frameworks, so must be some awfully light baggage

Admittedly I don't have a lot of experience with enterprise web development in Java but I love working with ASP.NET Core and I think it's come a long way since the mess of Web Forms and classic ASP.

What makes you think so? I'm actually curious