Are there still systems around with a /bin/sh binary?

/bin/sh is not always a symlink

NetBSD is one system where /bin/sh is not a symlink. The default install includes three shells: the Korn shell, the C shell, and a modified Almquist shell. Of these, the latter is installed only as /bin/sh.

Interix (the second POSIX subsystem for Windows NT) does not have /bin/sh as a symlink. A single binary of the MirBSD Korn shell is linked twice as /bin/sh and /bin/mksh.

FreeBSD and its derivative TrueOS (formerly PC-BSD) have the TENEX C shell as both /bin/csh and /bin/tcsh, and the Almquist shell as (only) /bin/sh. No symlink there, either.

OpenBSD has the (original) C shell as /bin/csh and the PD Korn shell linked thrice as /bin/sh, /bin/ksh, and /bin/rksh. Also no symlink.

Solaris 10 still has the legacy Bourne shell binary as /bin/sh, and this is definitely not a POSIX compatible shell.

Hopefully, Solaris 11 broke this annoying tradition by providing ksh93 as /bin/sh.

This OSX box has /bin/sh as:

$ ls -alF /bin/sh
-r-xr-xr-x  1 root  wheel  632672 May  5  2016 /bin/sh*
$ uname -a
Darwin AUS-LM-000421.local 15.6.0 Darwin Kernel Vers...