Why is losing the ability/interest in navigating through a paper map by hand bad, though?

Humanity has adopted and then discarded skills many times in its history. There were once many master archers, nobody outside of one crazy Danish guy has mastered archery for hundreds of years. That isn't bad, nobody cares, nothing of value was lost.

What we call knowledge work is a bit different to archery though.

Writing for example is proven to be better done by hand with a pen and paper, people who take typed notes don’t retain as much.

AI has accelerated the most simple and obvious answers to easy questions.

For more difficult things deep thinking and writing, partly with pen and paper notes and diagrams are still the most effective tools.