That's what's actually fairly impressive about C# being #1 on plaintext. Both ASP.NET and Kestrel (the frontend server) are both fully in managed code.
Various teams at Microsoft should be congratulated for their efforts. A few years back, ASP.NET was last (or near last) on this benchmark for simple, plaintext requests. They've come a long way and put some serious engineering into their system.
You can't even imagine. A goal has been set by the management to get specific results on some benchmarks, by improving the framework. We have weekly meetings to follow up on improvements and next tasks to keep track on these goals. And these meetings involve super qualified engineers and also brilliant open source contributors. I can t describe the level of technicity at each of these meetings. The impact on the framework is tremendous, you can follow it as our charts are public. And the goals are already reached, which is not yet reflected on TechEmpower as we only submit release bits. This is good for PR, but as much for also for any developper using dotnet.
Virtually every single item on my list is now completely irrelevant.
Although I'm not a daily developer using .NET anymore, I am astounded that such a turnaround was even possible. My hat is off to you and the teams you work with. Also, for the record C# is still a phenomenal language in my book.