There are Tesla owners on the Porsche forums who’ve complained about the seats in their Teslas as well. And in the Mercedes forums, people complain about their Porsche seat’s.I find these posts mind-boggling. After adjusting the 3 cushions on our seats with the controls on the side of the seats which then are saved under our names, my girlfriend and I think it is the most comfortable car seating we've ever used. She falls asleep next to me on any trip of length, every time. I'm at a loss for these folks.
So to a large degree, I think it all depends on where one is coming from and is used to, as well as personal fit.
Using Porsche as an example of how much difference personal fit makes, they have five seat types that get offered across all their models. Of the five, two are aimed at being the most comfortable: 14-way and 18-way adjustable seats. Very high quality seats in both cases, but very few Porsche owners appear to like both. They like one and strongly dislike the other.
In my case, I really like the 18-way seats and find them very comfortable for long drives. Whereas I find it hard to get comfortable in the 14-way seats and they become very uncomfortable to me after even a short while.
I cannot explain this, but it’s very common for folks who’ve experienced both. Few seem to like both seat types.
The moral is that one person’s happiness with seating is not a guarantee of comfort for other people. I guess Porsche understands that and thus they offer the various seating types.