<rant>
How about they ask you if you plan on putting a child seat in the back seat, if you dont they give you your car and schedule a recall when the parts are available if you want to do it (or the government mandates you have something you wont use).
If you do plan to, and cant bring yourself to the sky falling crisis of putting the child seat on the outer seat which have the tethers they hold your car so you dont do anything crazy and irresponsible.
Meanwhile everyone else can get on with life. Not having a centre tether doesnt make your car more unsafe on the road (apart from all EVs catch on fire, but thats unrelated)...
Its stuff like this with blanket rules which have good intentions, but annoy everyone else.
If i could opt to not have ISOfix or top tethers i would. Why should adults in the back seat have to put up with those stupid plastic caps digging into our butts when we sit there? I think Tesla have actually concealed the lower isofix mounts, which is an awesome detail.
Sure, make it so the car cant carry baby capsules and if you try to, well you cant. If someone says "can i put my baby seat in you car" you have a really good excuse to tell them to piss off.
Im not even sure that ommiting things in cars like these would reduce the sale value, its something that people having kids need, and it should be available, but we are adults buying these cars...
</rant>