Uhh...they last at least a decade, which is also why for the longest time they had a 10-year powertrain warranty (as required by law to help the transition.)

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.

Battery management software on hybrids keep the battery cycling between roughly 40% and 80% until they age out and the bands have to increase. On plug-in hybrids it is managed a bit more complex, with a pocket of energy saved for the plug-in charging/driving. Same principle though.

Some manufacturers use their software to prevent the battery from fully charging and discharging but it is not required or used by all manufacturers. When it is used it effectively limits your battery capacity in the same way a degraded battery is limited. So it is the same result.

Also, since the engine in a hybrid does not have to run a full duty-cycle, nor run at high RPM/power levels as frequently as an ICE-only vehicle, the engine also has a longer more gentle life.

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.

Not to mention, what you’re describing is what has been known for decades as “city miles” as opposed to “highway miles”. The stop and go, starting and stopping maximizes the wear and tear on the engine and minimizes its lifespan.

Subarus need their headgaskets changed more frequently than a good hybrid would need batteries.

This is because Subarus use a unique engine design that no one else uses with head gaskets as a pattern failure.

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

Someone's been reading "I'm scared of the future" myth web sites.

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.

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

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.