I agree with a lot of your points.
My argument was simply that people aren't obsessed with the idea of superheroes looking 'young' anymore, and that most depictions of superheroes in the movies involve 40-something actors. This is in contrast to what was the stated goal, in the comics and in adaptations, for a long time that to be ''fresh'' and ''relevant'' superheroes needed to be rebooted to be young 20-somethings (with even 30 being regarded as 'old'). That was the philosophy behind the New 52. Its also the reason why Spider-Man hasn't gotten past high school for the last two reboots (though I hope Tom Holland gets to stay in the role for a long while and change that).
For a long time after the Post-COIE reboot, people had a vague idea of an experienced Superman being around 35 (the official timelines DC published matched up to that). The New 52 screamed ''That's too old!" So Superman got rebooted into being around 27, and got ''cosmically divorced''
But now we have a Superman who, in terms of the new timeline and his role as father to a pre-teen (now artificially aged up) son, has to be
at least 40. And you know what? I think people are fine with it. Why wouldn't they be when they're clamouring for Henry Cavill, who's a few years shy of 40, to reprise his role? And Tyler Hoechlin may be 33, but he's playing a Superman who's canonically closer to 40 (more likely well past it), and who's the father of two teenage sons.
The fear of turning characters older is going away. And when your 'mainstream' superheroes are 40-somethings and not in their late 20's/early 30's, you have the potential for multiple generations of characters to co-exist, for younger heroes to age and step up to the plate, for a real sense of legacy.