Why?
A phone or laptop physical presence of raw material is only a few dollars, but still even that why is material worth any money at all, you just need to dig into the ground and get it.
So this stuff cost money because of shifting of data and legal rights.
You need to have someone agree to dig in their property to mine for the materials. You will need for people agree to do the labor of mining the stuff. you will need to people to agree to forge the material into a more useful method... All the value in a physical device is about license agreements of people will do the work for money that they will be able to trade with others.
Music isn't free to produce either. The musician has expenses that needs to be paid for, the data needs to be recorded edited produced... So a lot of people need to get paid for this as well.
You can tout that the record companies are making disproportional money... But people are paying the price, so complaining about that isn't the issue. A piece of digital data is valuable as a piece of equipment.
The real issues comes down to the fact that Supply and Demand. Digital Data can be copied exactly so cheaply that the Supply is nearly infinite, causing the actual price to go below the cost of creating it. So the companies try to put these barriers to limit supply as keep this data to be sustainable.