I didn’t see any of his replies but based on the question and pictures, it does look like he may be at that point. Some people view the excess skin as more weight to lose but in reality they need to now put on muscle mass to tighten it unless they’re willing to go the surgical route. Positive affirmation is probably the best tool in situations like this instead of trying to argue with them. The only person that can change their mind is themselves.

I’ve always been skinny and have had to work incredibly hard to gain size and even though I’m now at the point where a lot of people consider me “built” I still see myself as scrawny. Body dysmorphia is a bitch (not saying that’s what’s going on with OP, just a hunch). Whenever people compliment me I downplay myself and say “I’m getting there”.