You forgot to mention about how when you have young children and your partner pulls this weaponized incompetence bullshit, the kids learn it. Then they're doing it too. All the damn time. Now you've got multiple people complaining nonstop over every little thing. You'll drift toward doing everything just so they'll shut up for 5 fucking minutes. Now you're your partners bangmaid. You'll start to have outbursts from the stress and exhaustion of it all. Then you'll feel guilty for being unreasonable and he'll start badmouthing you too all your peers and any other woman he thinks is attractive. Now youre a cow who changed from the girl he married. Then he has an affair because having sex with him makes you feel like a pedophile because he has to be taken care of. You can't count on him for anything.
Now you're in marriage counseling and you both resent each other. It's too late. No amount of therapy is going to fix this. So you divorce and you get stuck with the kids when he made motherhood a daily torture for you. You helped him do it. Since you couldn't count on him for anything else during the entirety of your marriage unless you count being a constant whining jerk, counting on him for child support would just be bonkers.
You're still chasing him down trying to get him to be an adult.
And that's the familiar spiral. Yeah?
Hope your friend's daughter doesn't have any kids with this guy. She's in for a rough go of it if she does.
Weaponized incompetence is emotional abuse. Plain and simple.