Ok, I've just retired from 25 years in the car business and I'll share a few thoughts...
Modern engines and drivetrains are indeed at the pinnacle of combustion engineering.
Having said that, be advised that the ONLY goal in their design is fuel economy. Every other parameter falls to the side except fuel economy. Every decision during design is is tested against the alter of CAFE.
Do you know that the EcoBoost engines in the F150 have plastic engine oil pans? The engine oil drain plug is a disposable plastic, half/turn to lock, one time use, shit show? Indeed, most external parts are now plastic including, but not limited to, valve covers, intake manifold, thermostat housing, oil pans,(both engine and auto transmission), oil dipsticks,etc. In addition, both oil pump and timing belts now run wet by design. Wet as in oil soaked, by design. What can go wrong?
Many of you already know this, and the younger among us, accept it without note.
Here's a little advice, try "I Do Cars" on YouTube. Look for the engine you're considering and watch the host tear down, and comment on the engine. I learn something ever time I watch this channel.
Sorry for the rant
It's a fair point. CAFE ratings are incredibly important, as seems to be 'making more power than the outgoing model', and 'minimizing NVH'. Some of the decisions to achieve that, such as wet timing belts just to gain 0.01mpg and slightly reduce noise in operation don't seem like a good call from a reliability perspective. Neither do some of the cost cutting measures like plastic oil pans.
And yet, despite that, they
do hold up. Far better than the cars of the past. I started driving in 2013. As with basically every new driver in the UK, my first car was a cheap, mid 2000's hatchback, bought second hand with lots of miles. A 2004 Vauxhall Corsa with 80,000 on the clock in my case. My mother and I went halves on the purchase and we paid less than GBP3000 for it.
I did 100k miles in that crappy Corsa from 2013-2016. I only ever opened the hood to check oil (it never burnt any) and top off washer fluid. Other maintenance? Tires, brake pads, brake fluid when I cooked it on a track day. That's it.
My friends who didn't care about cars had similar 2000's models from VW, Ford, Renault, Toyota, Hyundai, and didn't even do that much maintenance. Between the 10-15 people who spring to mind, we probably did around 1 million miles. None of us ever had any mechanical issues. At all.
Since those days, I've bought four more modern cars from four different manufacturers (BMW, VW, Dodge, Subaru), three motorbikes (all Yamaha), and done another 150k miles. All of them have been totally reliable. No issues whatsoever. But then, they're modern cars and bikes, that's the expectation.
If I ever buy a car and it does have even the slightest hint of mechanical issues, the car will be sold and chances are, the brand is dead to me. My father had an old Freelander which had some minor electrical gremlins and now I'm very distrustful of Land Rovers as an example.
I don't think it's a surprise that my generation is completely mechanically inept. We never had reason to learn. Things simply don't break. I have friends who take their car in for a service once a year and have NEVER opened the hood in their entire life. That simply wasn't possible 30-40 years ago.
I contrast this to my one friend at college who ran a 'classic'. A 1979 Mini Cooper. That 70's car was temperamental. My friend spent time fiddling with carbs. It didn't start when it was cold out. It burnt oil. It fouled spark plugs. It had electrical issues. From what I understand from my father and grandfather, those were the facts of life on all cars in the 70's and 80's. Things needed a bit of TLC, it was normal to need to crack open the hood and check on stuff every now and again.
These days that's totally unacceptable to the mainstream consumer base. Advances in reliability have enabled that, and I think it's pretty amazing really, especially when you think how much complexity they've added during that period, the performance that those engines offer, the amount of stupid crap they have to make them do for emissions, fuel efficiency, and to meet consumer expectations around smoothness and power.
