I'm not trying to be mean... in fact quite the opposite.
Johnny looks sick. Like he either has cancer or a serious drug issue, in my opinion. The drug issue wouldn't surprise me, sadly. He's been through a lot. It all seemed to begin with his very nasty divorce to Amber Heard (not that he's a victim there just saying it's a lot to go through). Since then he's made BAD movies and has been touring full time with the band Hollywood Vampires.
From the looks of the pics, he's living that hard rock star road life too.
Rumors have been running rampant alleging alcohol abuse and other drugs. I just wouldn't be surprised at this point if he really does have a problem. I mean just look at these recent pics of him...
Now it's possible he's losing weight for a movie role, which some actors do to extreme measures. Still, the rumors make it worrisome. I hope he's OK.