That seems a bit misleading of a comparison IMO and only one case (JSON serialisation) when I look at their data. You are also linking to a round from two years ago which is out of date. It's also showing a lot of frameworks that are not that mature and not well used in the Java camp vs ASP.NET that is widely used, full featured, has a lot of bells and whistles and a lot of plugins available for most technologies and standards. All of which could have negatively influenced performance, even the hooks to allow them to be injected in can do so even if not enabled. The fact that a full featured web framework makes it close to the top (sometimes the top) over several rounds over many of their categories of use cases I can't discount as pretty good.

i.e. Its hard to read benchmarks without context of each framework shown, the compromises they have taken, how usable it actually is for building software vs just a benchmark, what shortcuts are done in the benchmark, how idiomatic is the code, etc.

https://www.techempower.com/benchmarks/#section=data-r20&hw=...

My personal experience having worked on both platforms for several years is that Java is easier to get to an acceptable performance, but the .NET runtime when you have to put the effort in has a higher upper bound of performance. It just has more tools in the CLR to work with than the JVM (e.g. value types, proper generics, spans, and more) so you can express something with a little more mechanical sympathy. Java is left with some decisions from legacy IMO that by default hurt its performance (i.e. lots of default boxing has hurt me before especially with generics). With .NET Core and future versions I think .NET is also taking up Java's default perf area as well. YMMV but if I'm worried about performance being a risk in my project .NET gives me more tools to optimize it IMO should that risk eventuate.