the propaganda works because we are all familiar with the smartphone battery degradation after 2 years, so it seems logical that same thing will happen with car batteries
It was very common in the 2012-2018 era. Batteries have gotten larger (less cycles) and better (sustain more cycles before losing capacity) since then.
Also phones don't have the same sophisticated circuitry or devices as a car to keep batteries in an optimal state, e.g. Nissan Leaf gen 1, which had significant range losses (on top of having a small range to begin with).
This is very true. There's also a habit where people are reluctant to get their vehicles batteries low as well. Folks seem reluctant to get below 20%. I think it comes from learned behavior from smartphones.
I haven’t experienced this for years.