It very much depends what the use case is. I find that a lot of the text processing I do is easier to use back references or other regexy things.
Having said this, I use tools that make regexes easy to use and readily available - I think in many programming languages the syntax means that other solutions are just as easy to devise and implement.
If you are a solo dev, you do you, but if you are working in a team and you are building huge regexes with back references and other bells and whistles... I would guess it's not very readable for your teammates. At least for me, when I look at such a regex I have to stare at it for minutes before grokking it.
Regexps are fairly terse and replace a lot of code, compared to most languages they probably have an information density at somewhere between 10x-100x higher (i.e. it's not rare to replace 100 lines of code with 1 regex), so I think it's fair to expect it take longer to unpack their meaning.
Wold that be a reasonable time to ping that coworker and ask them "what does this do?". Not because you can't figure it out, but because they already know?
Having said this, I use tools that make regexes easy to use and readily available - I think in many programming languages the syntax means that other solutions are just as easy to devise and implement.