That's a complete misunderstanding of what Tesla did. Having a component in the car that is 48V and having the whole car being on a 48V PoE architecture are totally different things. The sad part is that these company actually have the beginning of a 48V system but never actually pushed threw and did it all.
This is like when SpaceX landed a first stage and everybody was like 'DC-X did it SpaceX did nothing new'.
There is a reason lots of people, including experts are exited of what Tesla did here.
Of course Tesla has taken it further which is interesting and could be useful - but it's not quite true that the whole car is on 48V, they've already said that ~20% of the common / supplier-provided components are still 12V. For pure EVs, sticking with higher voltage makes a lot of sense and Tesla was perfectly suited to lead the charge here since they have built so much of their supply chain from scratch and can spec everything to be 48V where other EV manufacturers mostly just reused components from their ICE cars.
Previous 48V systems were only partial for good reason as well - traditional manufacturers have been using "mild hybrid" 48V systems since ~2001. Many of the electrical components on ICE vehicles are parasitic engine loads since they need power than can be provided with 12V, so e.g. the water pump and AC compressor have separate belts that always are 'robbing' the engine power regardless if they're needed or not. Adding that 48V system allows for the engine to be freed from the draw that those components require and adding some light regenerative braking is sufficient to keep the batteries supplying that system charged.
That these 48v systems aren't universal should provide some color on how successful / important the manufacturers had found them to be.
This is like when SpaceX landed a first stage and everybody was like 'DC-X did it SpaceX did nothing new'.
There is a reason lots of people, including experts are exited of what Tesla did here.