This is just insane. Not only are cars themself mostly unnecessary, if the right infrastructure is provided, but SUVs also use more resources to run and be produced then small cars, without any advantage over them. So an obvious waste, which could easily be cut to reduce emissions.
Source IEA: https://www.iea.org/commentaries/suvs-are-setting-new-sales-records-each-year-and-so-are-their-emissions
I don't understand your logic. Say SUV's were on average 50 % worse emitters than regular cars. Now when picking a car you face the choice of emitting 1 unit or 1.5 units of emissions, for basically the same service. If we look around, these kinds of choices are everywhere. Transportation, food, housing, electric power. Often the difference is even bigger than 50 %. Being consistent in choosing/forcing/promoting the better alternative results in a HUGE difference. Of course, if you look at one decision, it's not decisive. But transportation and cars definitely are a major factor.