There are people with full head of hair whose careers have been over in entertainment industry. There are people who went bald but that didn't impact their career. How can you reduce complex set of reasons behind end of a career to "it's because of hairloss" is beyond me. Sometimes, "It's because of hair" is just as ridiculous as "It's just hair".
He's just being REAL, bro! Someday you'll stop all this positivity and face the dark truth ...
But seriously, that last sentence is gold, couldn't have said it better.
On top of that, OP picked the 2 worst pictures that can be found of Muniz's hair, he normally looks nowhere near this bad, I just have no idea what he was thinking with that haircut. There's plenty of actors with as much recession and somewhat as much thinning, and people don't even have a clue just because of how they style it (and I just mean styling it, not to mention the vast amount who go one further and conceal etc.). If Muniz had half a clue he could still have this, only a few years ago:
By no means a desirable hairline but as long as it gives the impression of hair, a lot of people don't notice. Is it any worse than Jesse Pinkman?
Since Breaking Bad, Aaron Paul is doing tons of filming, and if you don't think about his hair loss and focus on it like in a picture above, you don't even realise just how bad it is (no pun intended). He's got 6 years on Muniz so you could say he's outside of that "weird balding youth" category but he's had a poor hairline for years.
Basically, there's a lot of factors as to why either actor is working or isn't working, and Muniz was a comedic child actor, becoming even a comedic adult actor is a completely different thing. He might suck, basically.
And judging by the one delivery of a line in this trailer that must have been his best showcasing of acting skills, yes he does suck.
https://www.youtube.com/watch?v=ukWGVNdPLEw
