Elon’s idea was great, but he also had the advantage of being first. When the roadster came out there were no other premium electric cars, so it could dominate that (small) market.
Now the FF91 needs to justify why it’s more expensive than every car Tesla sells, the iPace, and the Taycan (which should be available when the FF91 was set to go on sale). In all those cases the FF91 is at least 2x more expensive, and all those cars are made by companies with established records.
Jumping in and selling a premium EV now is almost as hard as selling a premium SUV from nothing. It can be done, but holy crap it’ll be hard.