i'm starting to feel that REPL driven development can be bad for maintenance, when you have a REPL, you can write ridiculously compact and abstract code that is hard to understand just by reading it.
That is a slightly shallow take though because its not really symmetrical like that. You can use a REPL as a way to arrive at the most easily understood rendition of something. But that is very prone to subjective bias as lots of things seem obvious in retrospect that are not at the start.
To the extent that the answer you eventually arrived at is a result of learning a mental model of the data and functions surround it, it will leave a significant residual gap for the next person who comes a long to bridge.
When using the REPL you can quickly experiment until it does what you want, but you need the discipline to distill something maintainable from it afterwards.
For a maintenance provrammer against learning anything, abstract and compact are always bad.
Typically though, if you understand a few core concepts abstract and compact can be more readable towards the end goal of a high level understanding.