Actually, sending the least experienced technician to your house first is an intentional tactic. My father is a retired HVAC person of more than 40 years. He used to work for small family owned shops but the big companies (like gas companies) began buying up the shops in various areas. Then providing HVAC service plans via your gas bills.

They would load up on young guys and keep one or two old guys. They'd always send the young guys first because they were paid about 1/5th of the amount of the old guys per hour. If they fixed things correctly, then they made more profit. If they didn't fix things, you still paid the hourly rate anyway. After the revolving technicians of various skills attempted to fix (and charge you anyway), they would eventually send in the senior guy to actually perform the repair.

Most of the repairs are easy and minor. Nowadays furnaces have circuit boards with LED lights indicating the problem. So it's mostly just replacement of a known part. So most of the time they made a lot of profit by sending the youngest/cheapest guys.

Protip: Those LEDs are often enough for the homeowner to fix the problem themselves. Most furnace problems are pretty simple to correct once you know what's wrong. The simple controller that just blinks an error code (codes listed inside the panel) is more help than we've ever had before.

Also, the older guys are probably doing construction work and making more money.

This brings up an interesting side point. I'm not sure if it's the same everywhere, but in the state I reside there are two sides to the trade professions.

One side is the service side. This is typically non-union and employees are trained at vocational schools that specialize in some field of expertise.

The other side is the new construction side. This is typically union and employees are trained via schooling and apprenticeships provided by the union itself.

In general, the union/new construction side makes more money, but, it's harder to get into the union and you generally work less hours (and make less money) until you are a fairly senior person. The non-union/service side will make more money (and work more hours) at least initially. The service side has very high turnover of youngsters.

Sounds just like offshoring your code.

Or, for a more direct analogy, the various tiers of support you get from any help line.