Silly question, but I’ll ask it anyway.

Not very well if the wire is of type 1) distributed (carbon core) or 2) fixed resistor.  They have more resistance than copper to reduce RFI interference.  It does not matter at 100,000 volts in the car but it does in an amplifier.

I am not aware of any fixed resistor in ages, and copper, not in forever except for racing, and even then you want to control the spark to prevent fuel cavitation.
Most domestic wire is not simply a fiber glass core covered in carbon filled latex. Most are variable spaced fairly high resistance stainless wire. They variable spacing is so they can have consistent performance independent of wire length, hence why today you buy vehicle specific wire sets (or should).
Don't pick some random site on the web for your information. Most mechanics won't have a clue about the inner working of spark plug wires.

Say who has better sparkling high fidelity speaker wires? Nascar or NHRA? AutoZone or Riley Autoparts? Will carbon resist electron puddling? So many things to consider here!

Just wondering, but can you make an interconnect with spark plug wire?

why is or isn’t this done?

I do have to ask this question though....

Why/how on earth did you even come up with the question to begin with?

I work on old Porsche’s. I was installing new wires on my 944 Turbo last weekend. The next day I made some interconnects with Duelund wire. The soldering iron was next to where I placed the old spark plug wires. Imagination took over from there. Voila, question;)