In most cases extended POSIX regexes are enough and looks the same as perl regexes.
I also used perl until I needed to write highly portable scripts that can be run on systems without perl interpreter (e.g. some minimal linux containers). Simple things are also simple to do with grep/sed/awk, more complex things can be done with awk but require a longer code in comparison with perl.
Systems with bash but without standard POSIX utils? I know some without bash (freebsd by default, busybox based distros etc.) and with grep, sed and awk, but not vice versa.