Abs are aesthetically pleasing on a universal level. They tell the story of a person who spent a large amount of time dedicating themselves to the discipline of working out, dieting, and learning about your own body. And that story behind a lean-muscular physique is sexy.
My gripe with abs in comics is that they are drawn onto a character like they are simply a character design. In order to be lean an muscular, SO MUCH time and work is dedicated to wearing the fuck out of your body and restricting what you eat. If you are a child and your metabolism is fast, you can eat like shit, workout, and still have muscle mass while being lean because your genetics are good (which is not the majority of people). But as you get older, your metabolism will slow down, making it harder for you to get abs. If you're 28, you don't have abs by waking up, going to work, drinking alcohol with your buddies, party, and go to sleep. You force yourself to fit working out into your lifestyle several days out of the entire week. It's dedication.
The Broader Picture
I don't think illustrators who want to make their characters walking thirst traps are really doing anything wrong, but they can be promoting some problematic beauty standards to the people that read their work. For example, in all of those poor-girl-rich-CEO stories, the CEO guy is pretty young, rich, handsome, and HAS ABS. Being a CEO are a 20-something year old is already stressful enough, but even if that business has generated enough money for you to have enough free time to workout, there's no point. But if a CEO felt as if his money, face, and height wasn't enough to attract a woman, working out hard enough to get abs still takes a lot of fucking time and effort, and months to YEARS to show results. That's what I want artists to portray.
Most of us as comic readers sit on our asses for hours at a time and see good-looking characters that have "perfect bodies" but we don't see the characters really working out to maintain those physiques, let alone dieting, and struggling. We see these characters and say, "Wow that person is hot. I wish I looked like that, but I don't look like that now" not understanding that a real human would have to dedicate a lot of time to look like that. Plus, the way your abs show up is a genetic gamble because 10 people can have the same bodyfat percentage and muscle-mass, but their abs can look completely different. Not only that, but these physiques are portrayed as dominating and strong. But in truth, bodybuilding can genuinely suck the fucking life out of you. (Fun-fact: many men who body-build lose a lot of energy and can develop temporary erectile dysfunction). And in truth, muscular dad-bods can be way stronger. And lean guys with no muscle can have more energy and a better quality of life.
Just know that no matter your sex, gender expression, age, etc, you can still be strong and attractive in your own way. Whether you're ripped or pudgy, weather you're bodyfat percentage is 7% or 32%. Whether you have 2 jobs or whether you're living in your parents' basement. Look at the fucking Paralympics. Try working out more often if you have time and the ability to do so. Take a brisk jog around your block or do squats in your apartment. Do it for your health, and not just for aesthetics.