I’ve got 3 kids under 5. Car seats are absolutely enormous these days — it’s impossible to fit 3 across in even the largest “crossovers” (VW Atlas / KIA Telluride). I don’t want a big car (my dream car is something along the lines of the Audi A4 Allroad Saloon) but I also sometimes need to bring all my kids to the same place.
Figure out a way to safely downsize car seats and I bet SUV purchases would drop 10% or more.