Do you consider cables to be a "component" of your system?

Yes, of course. 

After all I've been through.....yes.

yes, as i do the room, the rack, power supply and so on ... it all matters

but experience tells you what aspects matter more vs less... so as not to let the tail be wagging the dog... just like in life, smart folks know what is really important, and don’t sweat the little stuff unnecessarily, or let worries about such get out of proportion

I do consider them to be a part of my system. But my room is a much bigger part of my system. In my opinion, one really cannot know what cable choices to make until one has stabilized the room factor. Some cannot change their rooms, but if they can, they should do the room first before trying to fix problems with cables. 

There is a lot of focus on an umbilical cable used for connecting devices.

These are essential and when the correct ones are discovered, are Capable of creating a impression that seemingly is a benefit to system.

These are only one proportion of the Signal Path, and there are other considerations that can create an impression that rises above the impression the Cable can make.

There is the Visual element that can be easily identified and the element that requires a more invasive approach.

The Cables Connectors either RCA or XLR can be looked at, Low Mass with Pure Copper Pins, is in my mind, the most desirable metal to be used for the Connectors Pins. Searching the Web can find connectors with OCC Pins in use.

The RCA or XLR Connectors on the Chassis are, in my mind, best if Low Mass, Low Eddy and with Pure Copper Pins . Searching the Web can find connectors with OCC Pins in use.

There are Copper and Silver Wires today produced as OCC and there are later Generation Design Wires such as PC Triple C.

Wires from the three above, used on the circuits signal path will be quite capable of offering a presentation that will really show off a well thought out selection for a Umbilical Cable and its assembly, especially if the Connectors used on both Cable and Chassis are used that are a high performance spec'.

These methods are not usually seen as a discussion, but when the experience of such changes are encountered, the impact of these is quite mind boggling and a real head scratcher.

Trying to describe how a couple of small changes has made such a forceful impression, where betterment is undoubtedly present, is not a subject I excel at, but luckily I converse with some who can make it known quite comprehensibly in a layman's wording. I have no dispute about the descriptions on offer, it certainly matches the impression made at the time of demonstration.