Mercedes showed with the EQS concept that they can make a very good looking EV if they want, that car already had production car proportions, it wouldn’t be difficult to just put it in production, so the less attractive production EQS and the rest seem to look like that by decision - and I think they will all look less attractive than the current ICE lineup of their alternatives at Mercedes. Battery and EV tech is not yet much more preferred over ICE, so Mercedes will have way more money from their traditional models for quite a few years, thus there is no sense to cannibalize the sales. I agree that with the current S class, Maybach, then SL they will reach quite a peak in their design language, but there is a chance that the next gen ICE models (the few which will be made) will have less attractive designs, and then they will put their best work into the EQ line, which by then will overtake the sales of the traditional models. Mercedes has the EQC now, and will present 7 new electric cars next year - they will be on the market with quite a lineup of cars, and I think that’s all they need for now, presence, not domination.
Porsche has the Taycan, and the Audi GT is coming out soon as well, but both brands have less cars than Mercedes and both of these cars happen to be original, not competing with their other models, so the case is a bit different.