Cygwin was great in 2005, but I don't think they've been playing to win ever since.
The environment they are in is changing and they haven't been putting the effort in to keep up.
WSL was a "better cygwin" in many ways, although it was working at the syscall layer instead of the library layer.
I loved the old WSL but it had the fatal problem, in Microsoft's mind, that filesystem metadata operations on Windows are much slower than they are on Linux and there is no way around it if you want to use NTFS, use the Windows page cache, etc. If you're lucky you might live your life as a developer and not care, but if you're living with the wrong kind of build process on Linux, you will go to Windows and find your 2 minute build is more of a 1 hour build. (It never happened to me in core activities, but boy I ran into this problem with one-off data processing scripts)
Turning off the antivirus helps, but it turns out the filesystem interface in Windows is fundamentally slower than Linux for certain operations -- Microsoft thinks this stops some people from using WSL and they took the desperate act of bypassing the internal filesystem API and running the whole Linux kernel under a VM in WSL 2.
(Which probably chased away more developers than it attracted since WSL 2 is overall not so solid as WSL was for most tasks, and you can live a much more trouble-free life if you install Ubuntu under Hyper-V)