He's right though.

Mac & cheese really is unimpressive. Spaghetti Carbonara is way better, even with inaccurate ingredients (e.g. using bacon instead of guanciale or even pancetta).

Though if you do insist on making it 'Murican style, try melting the cheese into a bechamel sauce and adding some diced ham or cubed bacon. The former makes it way creamier, even if it ends up standing for a while, and the latter just adds some neat flavour and texture. Stick with ham and/or bacon, or maybe very few other things, otherwise it stops being mac & cheese imo.

I saw a story once of someone who asked internet strangers whether they were the asshole because they hated someone's mac & cheese. When they described what went into the stuff, it was full of added things, a quarter of which would already stop it from being mac & cheese, and half of which either conflict with each other, or are stuff which if they were the sole additive would give me a reason to nope out of the dish.

With both mac & cheese and spaghetti carbonara, I'd say less is more.