what causes a lot of misunderstanding is that there are 2 separate 'scales' of difficulty.

Macro difficulty - what can a low-level character do VS a high-level character

and micro difficulty - is this task more or less difficult in the moment than another task?

As for specialist characters just 'nuking' certain skill checks compared to 'laymen' characters, that just comes down to the GM's skill, imho.

This mostly only becomes an issue when using the 'video game' philosophy of level, erm... sorry, campaign design, where fixed challenges exist statically in a pre-determined environment and anyone can approach them if they like.