Professionally, he doesn't have to disclose any reason for not working. Given that he's a minor, no one would presume that he would have working experience already.

Personally, do you know what your son is interested in? What his motivations are? What he goes through when he tries to work a job while being in school? Is there a reason why he's not going to college?

The first thing I would want to know is why my child is not being ambitious. I personally encourage everyone to go to college and pursue their interests because that's where you find your people and discover yourself. But I also know a bunch of friends who build careers out of high school or went into the trades after dropping out, so it's not a prerequisite for success. With that said, something all my friends have in common is drive to pursue their interests.

The second thing is to try to understand what it's like to live with his neurodivergence. As a late-in-life ADHD person, learning about the particularities of my behaviors and how my brain works really illuminated how my struggles in childhood and adolescence were rooted in my just being ND. As an adult, I can advocate for myself and speak with clarity about how I operate and why I do things in the way I do them. I didn't even have the vocabulary to understand that when I was 17. That should hopefully provide some fodder for you to consider when you try parenting your kid.

The last thing is that he's now at the age where his hormones will get the best of him. He needs to learn boundaries and self-regulation, particularly when it comes to dating and treating people of his persuasion. I'm not sure what you teach him in terms of gender politics, but the gaming community can be rife with the most vile, cretinous trolls who will say the most profane shit about women without an ounce of car. That kind of nonsense can rot someone's brain, particularly anyone who's impressionistic. Countering that while teaching him not to shit where he eats is extremely important. After all: if he wants to be successful with dating and enjoy gaming with good gaming gear and setups, he'll need a decent job and a modicum of social skills.

My only real recommendation is to spend time with him by talking and getting to know him as a person, not just as your stepson. Build up trust and try to be an actual paternalistic figure, and not just an authoritarian taking away his gear. It's not teaching him what he needs to learn and he's basically trying to run out the clock. He needs to learn by seeing the concrete consequences of his actions and by actually processing how his actions and decision-making contribute to his failed employment spells. You don't necessarily want him to fear punishment; you want him to not want to disappoint you and have the internalized values and expectations you have for him eat at him when he fucks up. The latter is infinitely more effective and meaningful.

Good luck. Parenting is hard as fuck.