WoW64 is practically native because Windows keeps 32-bit copies of all system libraries for 32-bit binaries to refer to. There is a very minor performance hit when Windows thunks calls to SysWOW64 behind the curtains, but it's impossible to notice.
You can see it for yourself, the 32-bit libraries are stored at C:\Windows\SysWOW64; the 64-bit libraries are stored at C:\Windows\System32.
Yes, the naming dissonance is not missed. The glory of backwards compatibility. :V
You're probably using WoW64 right now and not realized it because it's so seamless; there are still plenty of new/current 32-bit programs including Steam and many games.
As for running a 30 year old program, it's not exactly 30 years old (yet!) but I run stuff like Winamp and Paint Shop Pro 5 daily without fuss to this day in Windows 11 thanks to Microsoft's devotion to backwards compatibility.
The older WoW which was based around NTVDM (NT Virtual DOS Machine) for running 16-bit programs on 32-bit Windows was actual emulation, as evidenced by the name.
