It sounds that you want commitment, marriage and children and you are direct about it. He either doesn’t want it now or doesn’t want it at all but his answer “idk” just isn’t good enough.

I agree with you that him not wanting to do things isn’t an issue.

His indifference and lack of commitment is an issue. I don’t recommend you wait for him to change his mind re marriage and children. I’d consider ending it and improving your mental health and your life in general without him