WSL1 was very conceptually appealing, and ended up working very poorly because of the poor matching between Linux syscalls and the Windows kernel. Git suffered terribly as a result. The inverse is also somewhat true - there have been cases where Wine is much slower than native Windows because Linux simply doesn't provide a simple way to achieve the same outcome, and interestingly the Wine developers have had reasonable (if tediously slow) success in making it possible to express the same semantics to Linux and have it handle things fast. It would be fascinating to know whether WSL1 developers didn't have enough traction to get Windows internals altered to match, or whether it's just way harder to do the same under Windows.
It's my understanding that a big part of WSL1 performance loss comes from the relatively thick layered filesystem architecture on Windows.
Since git and nodejs are both common in modern development and are expected to work efficiently with huge numbers of files, this was a real bottleneck and it couldn't easily be tackled without threatening backward compatibility.
Wine achieves better performance these days due to things like... adding a module to the Linux kernel that implements NT-like synchronization primitives. So, Linux subsystem for NT synchronization basically. (a.k.a. NTSync)
Maybe this works out better because Linux is more flexible, while Windows/NT is more "set in its ways" and therefore more difficult to implement Linux on top of... Maybe?