In certain situations, fundamentals may not matter, but very often, especially for long term learning, they really matter. Since this is a deeply held belief, perhaps moulded by experience, I find it tricky to articulate to an intelligent skeptic why they should bother learning fundamentals. They often have surprisingly strong rebuttals, including:
experts do not find such basic material interesting
I empathise: if someone in a specific niche is getting along just fine without understanding fundamentals, they may have no motivation to learn fundamentals, especially if they're already recognised as an expert (not necessarily by peers, but perhaps by students, clients, or consumers of their research).
What lines of reasoning or resources (preferably canonical ones) do you use to demonstrate the value of fundamentals to those who may be sceptical of the value in learning them?
This happens to be from a physicist, Richard Feynman:
In physics, when you discover new things, it looks more simple
(when) We learn about a greater experience .. the laws look complicated ... but .. every now and then we have these integrations .. (and) it turns out to be simpler that it looked before
The corollary being that when we understand something on a fundamental level, it's actually much easier to communicate, understand, model and predict.