Incidentally, there's going to be a massive jump in people driving bigger commercial vehicles anyway as gas vehicles get phased out for consumer use. A lot of big SUVs are the result of the regulatory regime already. Stupid regulations almost always make things worse.
This is such an ideological comment. The reality is that stupid regulations make things worse, but non-stupid regulations make things better. We want non-stupid regulations. A world without regulations is a non-starter due to the tragedy of the commons incentive problem. Imagine a world where dumping was legal because there were no regulations. Or where explosives could be purchased from your local corner store because they weren't regulated. It's a non-starter. You would be dead from a resulting illness or terrorist attack. Nobody wants it, including you. So if you can propose a regulation-free solution to the various incentive problems like tragedy of the commons, then I'm all ears, but the burden of proof is on you to do that, and it's a burden you haven't met.