I would argue it's sh (Bourne shell, or POSIX shell rather) than Bash, as Bash is not present by default on some notable Linux distros (Alpine Linux, OpenWRT et

I would argue it's sh (Bourne shell, or POSIX shell rather) than Bash, as Bash is not present by default on some notable Linux distros (Alpine Linux, OpenWRT etc.) and especially not present out of the box on many popular *BSD variants.