The need for a CDL is one obvious reason. It looks like the internet disagrees on whether CDL requirements start at class 6 or 7, so we're really only talking about 1-5. And I've definitely seen 4s and 5s on the highway that have probably never seen a spec of dirt in their life. So there are certainly some people just looking to get the biggest thing they can legally drive.

CDLs only apply for commercial use. You can drive a tractor without one if it's for personal use.

They require a special license.

But, in the USA, you can drive up to 26,000 GVW with a normal license, so everyone should be driving box trucks or similar.

Nothing in the parent's hypothesis implies that the normal mitigating factors like cost/practicality don't apply.

Also, size is only one prominent factor in masculinity. E.g. a pickup truck is frequently seen as more masculine than an RV.

What makes a vehicle masculine? I know plenty of women who own trucks who insist their truck isn’t.

Come on. Because they are exponentially more expensive to operate and much more complex to drive. You also can't park them easily, blah blah blah, CDL, blah blah. I get your sarcasm, but people buy the largest passenger vehicle because they fit within reason but still allow them to brandish themselves.

Assuming most don't offroad; There was a study that said trucks are used for hauling/offroad less than 20%~ more than once a year). I can't find it anymore so you can call me on that.

Lifting a truck reduces efficiency by creating drag and uplift (I believe that's what it's called). It also raises the center of gravity which greatly reduces handling and increases the possibility of rolling over

Chunky off-road tires wear out faster, are less efficient, and reduce handling on the road.

Extra lights, as well as lifting your truck without adjusting the lights, blind other drivers creating a safety hazard.

So more gas, more money, less safety for everyone, but the person stands out more, like large horns on animal, it's all about peacocking.

And yes, I know this is done in other ways, fancy loud sports cars, showing off money, clothing, etc. If that was going to your response, then I'll throw down the whataboutism card and do a double reverse move and point out those have less effect on the environment and safety. Yes, I know fast fashion is bad for the environment, kids in blahstan, but it's about levels not bad or good.