I don't know much about electronics but I think I am correct in saying that all wires ( and cables... but there is a difference..) exhibit resistance, inductance and capacitance. Therefore, in theory, they are filters. Some people also quote other parameters ( skin effect etc.)
The questions are of course:
1. How much of the above parameters can a meter or so of wire (or cable) actually impose on the signal?
2. Is the effect audible?
In my experience the answers are:
1. Seemingly not much.
and
2. No.
I dare say if a manufacturer deliberately makes a wire which has very high impedance, or capacitance etc., then they are not offering something which will 'improve', the signal, but something which will modify, or even damage the signal.
Of course, if a manufacturer insists that their amplifier 'needs' a specific cable.. they are either just touting for more cash, or they need to make a properly designed amp.
Far more useful (and a damned sight cheaper.) in my view, is proper 'dressing' of cables. Keep them away from each other, avoid crossing, and especially keep mains wires away from small signal wires where possible.
OTOH, I have a number of lengths of Orange Lawnmower cable.. some of it rare vintage stuff dating back literally decades. It has been 'conditioned, by long term use delivering AC current at 230v to a motor driving an unbalanced and very blunt metal rotary blade, so will need no burning in. Obviously I can't just give this stuff away... Make me an offer....
Mull