Ebikes are more prone to underinflation simply because the ebike driver (I didn't say cyclist) never notices a difference.
This is why most vehicle drivers rarely check air pressure. It doesn't put them out of breath.
Oh yes, I have seen ebikes out there where I can tell they only have about 10-15 psi in the tyres.
A cyclist that regularly does 15 miles daily would notice almost immediately that the tyres feel wrong as they are pedalling more watts.
This isn't some trip to the corner store half mile away. If I knew I was going to do 15 miles of pedalling, for sure I would top up my tyres. I always do.