I understand that Tesla sells a ton of cars, and will continue to do so. However, I don't think they make a better product, and it's certainly not luxury. That was the point I was responding to.

The important point is that "better" and "luxury" are subjective, distilled down to "value". I can't speak for those buying Teslas (disclosure: Tesla owner), but its clear it meets their requirements; the demand is validated. Everyone has their ideal and what is most suitable for their needs. Leather and fancy interiors for some, plastic spaceship rocket cars for others.

Why would people buy PHEVs in Germany? AFAIK there isn’t any meaningful incentive to do so, registering pure-ICE cars is already cheap enough.

1.59 euros per liter * 3.79 liters per gallon * 1.16 usd per euro is about 7 USD for a gallon of fuel. That's a pretty big incentive.