It wasn't that long ago that compariing .NET to Go was insane: Go was far faster but now it's a toss-up in some cases. Go still wins on small size of binary but in cloud workloads does it really matter if my lambda in go is half the memory and half the execution time when the "bigger, slower" C# version is still under 128MB and executing only a few milliseconds slower? In cloud cost terms the difference is small enough not to matter.
It tooks years and a lot of work for them to make it on part or faster, Go did not focus on performance recently. Also you should take benchmark with a grain of salt, every recent language can be fast nowdays.