Bash is ubiquitous - the best selling point for knowing it and sticking to it. I desire a fancy new shell but don’t want it to become a crutch, limiting my use

Bash is ubiquitous - the best selling point for knowing it and sticking to it. I desire a fancy new shell but don’t want it to become a crutch, limiting my usefulness and familiarity when I’m on a system lacking it.