The harder you blow, the faster the peas will move. The force that moves the electrons is called voltage. How well something conducts electricity is measured by its resistance. Resistance in wire depends on how thick it is, how long it is, and what it's made of. The lower the resistance of a wire, the better it conducts electricity.
Copper is used in many wires because it has a lower resistance than many other metals.
The wires in your walls, inside your lamps, and elsewhere are mostly copper. Remember the peas in the straw. If the inside of the straw is covered with honey, the peas are going to be very, very sticky. It's going to take a lot of huffing and puffing to move those peas or electrons. That's because the honey is holding them back.