I use sed and awk fairly frequently (and I'm familiar with the tools to the point where I got half a dozen problems into AoC with just sed once).
Most of what my sed and awk programs I write aren't supposed to be maintainable, but rather typically one-off stuff for-the-moment sort of thing. I'll grant it's append-only code, but if I need to do the same thing later (or something adjacent) I'll typically just write another oneliner since there's no real effort involved in it.
It's pretty much always more effort to write an actual script in some language like python, since it needs to be in a file and have a name and take arguments and so on.
Most of what my sed and awk programs I write aren't supposed to be maintainable, but rather typically one-off stuff for-the-moment sort of thing. I'll grant it's append-only code, but if I need to do the same thing later (or something adjacent) I'll typically just write another oneliner since there's no real effort involved in it.
It's pretty much always more effort to write an actual script in some language like python, since it needs to be in a file and have a name and take arguments and so on.