you do realize there are lots of ppl on this planet that either make more money/hour, and/or will use the "saved" time not doing things like building a pc, doing oil change themselves?
why would i waste about 1h (purchase parts, jack up car etc) to that, if i can pay someone 30-50$ to do it for me, while i work for 1h, making +100$.
Bad example: If I go to the dealership (or local car shop), get an Uber to my work, then uber-back to the dealership after hours to pickup my car, it would have cost more time / effort than just me doing the oil change / tire rotation in my garage. Its only 20-minutes to change oil and rotate tires. I get my shirt and pants dirty while doing so, but I make sure to wear bad clothes, and shower afterwards.
Besides, last time I sent my car to a local car shop (close to work), they overtorqued my tires to the point where I had to replace a my wheel-locks. And no, I wasn't going to give that shop more of my money for their mistake. Ended up costing me 4 hours to get a freaking oil-change + tire rotation instead of just the 20-minutes I do by myself. The money is peanuts, but the time costs are real when other people screw up your car. I'd probably spend the extra money and go to the dealership if I was ever to get someone else to touch my car again.
And by default, they pour in low-quality conventional oil. You gotta upgrade to synthetic oil (and in many cases, its synthetic-blend instead of pure synthetic). Asking them to ensure a proper full synthetic oil change vs a synthetic blend (etc. etc.) is a hassle compared to just buying synthetic oil and pouring it in myself.
---------
Its a similar issue with building a PC for me. I want a decent SSD with NVMe, a decent graphics card, an efficient power supply that can handle upgrades to future computers, etc. etc. By the time I'm done researching what parts I want, its faster if I build the PC myself than buying a premade one.
Premades are great for people who don't want to put in the effort into researching parts. But I'm a technology-nerd, I'm very interested in those details.
only in america are ppl told to come in for tire rotation (and most charge them money).
A front-wheel drive will have more tire-wear on the front tires. Brakes also shift the weight of the car forward (due to momentum), wearing out the front tires slightly more. Finally, American highways are designed with far more right-turns than left turns (the shear number of cloverleafs around here is outstanding). As such, the left-tires (the "outside" tire on a right-turn) wears out slightly more than the right tires.
Without rotating tires, your front left tire will die thousands of miles before your rear right tire under typical American (ie: highway driving with too many right-turns) scenarios.
I'd imagine that European roads are more balanced with maybe fewer highways? I don't really know. But American roads pretty much take a toll on the front-left tire, far more than other tires.