Have you ever laughed out loud at a cartoon? I don’t think I have, and I would say I enjoy cartoons quite a bit. A grin is about the best reaction I can give to one myself
I'm not sure I've ever laughed out loud at a cartoon, but as a kid, the compilation books of Charles Addams cartoons used to fill me with so much warm pleasure I would read them over and over, and his cartoons still just plain make me happy to this day. I can clearly see that Larson does that same thing for many people.
MAD is wacky. This is more England and it's casual gutter talk. All cultures have their own. Do you enjoy any British hum(o)ur?
VIZ is crass, puerile in the extreme, casually (insert your red line here)-ist on many levels, and often repetitive. It uses common slang words, so somewhat culturally revealing. It's 'wrong' on many levels but done with style, albeit sometimes a repugnant style - So you inwardly 'gasp' in revulsion but outwardly stifle a giggle.
The fake small ads are often very very funny.
Lastly, like so many gags that use the 'shock' effect, the humour doesn't last forever; take a look at an early one on Archive...
Generally, I agree with you. But I do remember coming across Parking Lot Is Full one night and having to stifle my laughing so I didn't wake up my wife who was sleeping next to me while I was reading it.