Agreed with your bolded line above. You can see how Millar's version COULD happen, it's not as bad as "The Boys", but still... but you can also see why Marvel made their movie characters way more likeable. As that equates to bankable. I mean, RDJ plays a kinda egotistical know-it-all jerk Iron Man at times, but you still like him. If he was just an outright jerk all the time, some may still like him, but AVG movie-goers wouldn't.
I'll chime in that the Ultimates has its ups and downs, but for me, some of it is just a little too abrasive. Especially the Hank/Jan dynamic. Maybe I'm just too used to the MCU now. I recall Cap being a class A jerk, too.