Back in 1981 we had to call Bell Canada because there was something wrong with our phones ??
(I cut the phone line.

)
When the Bell dude showed up, he reconnected the telephone wires with these,..
View attachment 210964
Silicone grease filled quick connectors.
He simply stuffed the two wires into the connector (without stripping off the insulation) a pressed the button.
The metal "blade" crimped the wire while the button squeezed the jelly all around the connection and out where the wires went in.
I remember seeing bare copper telephone wire at the junction box, and they were all dark brown with oxidation.
That's the kind of wire that won't take solder. It has to be cleaned off first.
If solder won't stick to dirty, corroded wires, then I would argue that electricity would also have a hard time conducting through the film of darkened oxidized copper.
Electronics and electricity are related but different.
The Cable TV guy was here last year and said that they are allowed to work with voltages up to 90 volts without a ticket.
Anything over 90 volts and it starts to tingle when you touch it.
The Cable lines operate at ~70 Volts.