It is the "Planned Obsolescence" program along with the big profit service scam.
I went to the Conroe Toyota dealership for my air bag recall a while back. While I sat in the waiting area, "Caring Service Writers" explained to the masses what services they needed. I was very close to saying "They are blowing smoke up your posterior parts", but I held my tongue. It wasn't easy to do.
They presented me with a list of items that I needed to address if "I wanted to keep my truck on the road".
It included a transmission service, $299.95, I paid Attkinson Toyota (Bryan,Tx) $109.95 for the recommended service. Spark plugs, $291.79, I bought 8 NGK iridium plugs for $60.00 and it took 30 minutes to replace them. Replace differential oil, 165.77, I let Attkinson do it with the transmission service for $55.00. They only wanted 1108.91 for the timing belt/water pump replacement but $186.42 was added in for the $15.00 serpentine belt replacement. You can not replace the timing belt without removing the serpentine belt (and radiator). I guarantee, they would have tacked on tension pulley's, cam shaft seals, coolant and more to the timing belt replacement. A $199.95 fuel injection and throttle body service was recommended and power steering fluid replacement was 129.95. I bought a $3 turkey baster and sucked the Power steering fluid out of the reservoir about 4 times and replaced 90% of it. Total cost less than $10.00.
Added to their estimate was 120.88 to diagnose that the 12 year old batteries in the TPMS were dead. I bought 5 new sensors when I replaced the tires last fall for $150.00
Not all dealerships are bad. I needed a few dash lights for my new to me 07 4Runner. $4.71 each in Bryan and Huntsville, $8 something in Conroe. I told them I would go to Bryan for the bulbs and didn't see any reason to do business them any longer.
I replaced my timing belt, water pump, thermostat, tension pulleys, spark plugs, coolant hoses, coolant, trans fluid, P/S fluid, differential oil, serpentine belt and the tire sensors for in my 05 Tundra truck for about $750.00. Other than tires, one front brake job and oil changes, this was the first time I spent any maintenance $. Way less than the 3k+ the sleazy dealership wanted.
I am glad I can do almost any vehicle service myself, but knowledge is power. Even if you don't have the tools/skills, learning how mechanical systems work can save you thousands over your lifetime. rh