The federal law was 8 years not 10 and that did not include what they call “normal wear and tear” from the battery fully charging and depleting. So the batteries still degrade in less than 8 years and are not covered by the warranty.

Ooh, correct there on the 8 year mark, I was wrong! Until recently I'd not met a main stream hybrid without a 10-year powertrain warranty. Guess they were just going above and beyond.

That being said, I've also yet to meet a hybrid owner who's battery didn't make it a full 10 years or more. Those people do, I'm sure, exist, and the batteries do age out. A person I know had a (older than 10 year) cold-winter HV battery too low to start ICE scenario, but that will happen with any vehicle if any battery ages and is cold. (As hybrids use the HV battery to start the engine, not the 12v battery.) Anecdotes are only as good as the statistical input data, however.

Engines experience the most wear and tear on start up because until the engine is turning, the oil isn’t pumping so on start up the internal parts of the engine are lubricated the least. So hybrids maximize the wear and tear on gas engines.

Yes, but. Modern hybrids have electric oil pumps, and unlike traditional ICE engines that use a starter motor that engages the flywheel with a solenoid, they just gently spin the engine with power from one of the motor-generators (on Toyota-style prius/camry/etc the most common design). The engine can be gently spun up to speed and then spark applied. Much more gentle than traditional start-stop, even from those cars that have that annoying engine-stop-start feature. They also use very low-weight oil to reduce friction. They manage the engine heat to ensure everything stays at optimum temperatures. They can switch between the Atkinson cycle and Otto cycle as needed for both efficiency and heating. In very cold weather, for example, the engine will run more frequently to keep it warm (as well as the passengers.) And again, they never reach the load an ICE-only vehicle hits, except some edge-case scenarios like an hour-long mountain climb that depletes the HV battery and the engine has to rev higher to compensate.

Using it in a hybrid means you’re paying for the head gaskets and the hybrid systems failures.

Only on Subaru boxer WWII engines though, although they were probably a bad example, as there are many other ICE manufacturers that do not suffer their fate, ICE-only or hybrid. I suppose that means stay away from Subaru hybrids?

I’ve been a master mechanic for over 20 years now. I’m certified in hybrids and EVs and spent a lot of time working on used cars. That’s what I’m basing my comments on.

Hey, props to that real-world knowledge, as I said previous, I'm sure there are cases where that does happen. Maybe I live in a bubble of successfully-lived hybrids. The people I know also properly perform regular maintenance, so maybe that is an additional factor. I bet you've seen some horror stories.

Like clockwork, hybrid vehicle owners sell their vehicles before the power train warranty is up because warranties don’t cover normal wear and tear.

Vehicle owners are fickle in general, like new cars, and don't like high repair bills or regular maintenance. Most never keep a car for 8 or 10 years. Either way that will always happen with any type of vehicle. For anyone worth their salt, a refurb battery can be purchased for much less than OEM new, and often the biggest issue is corrosion or some dead cells in a pack, both of which can be mitigated. There are also hybrid shops that can refurb the existing battery. All sorts of options. I get your point though, one is maintaining two systems, not one, and with all the falsely-inflated prices of vehicle parts since the pandemic, anything is expensive.

Hybrids have two drive trains with twice the maintenance and part failures. Both drivetrains operate under the worst conditions (fully charge/deplete, start/stop) so when they start to break down it is twice as expensive.

Hybrids (most) have one drivetrain that is shared across power sources/sinks. Battery is never fully depleted, nor fully charged, as mentioned previously. In fact, the battery can not ever be fully depleted, as it is the power source used to start the engine from a cold-start. (The little status indicators on the dashboard, if one enables them, do not even show the true state of charge, they just show a feel-good full/empty based on the current battery parameters.) Even stopping an engine on a hybrid is a much gentler affair than a pure ICE. The engine gently spins down and the power is absorbed into the hybrid system. Slightly rotated if necessary to make start easier, and then it sits and waits.

Other fun things, a friend with a 2004-2021 hybrid never had to replace their brake pads once, as the friction material never degraded enough due to regen braking. Brakes are cheap, of course, but a nice perk.

But don't take my word for it:

https://www.greencarreports.com/news/1099135_toyota-prius-taxi-logs-more-than-600000-miles-batteries-last-apparently-video

https://www.detroitnews.com/story/business/autos/ford/2019/09/06/road-test-2012-ford-hybrid-new-york-taxi/2142119001/

https://www.electricbike.com/the-curious-case-of-the-600000-mile-hybrid-electric-taxi/