Seriously, nobody has mentioned House yet? A brilliant doctor who pops Vicodin like they’re tic-tacs? Although it’s not like the other characters didn’t try to get him to stop, and that he didn’t occasionally suffer the consequences of his addiction. But I think they all realized at some point they were fighting a losing battle.
Perhaps nobody has mentioned House yet precisely because the other characters tried to get him to stop? Not a great example of no one cares.
[Bolding mine] yeah, that one doesn’t fit the OP “…no one cares”.
Edit: Geez, been gettin’ ninja’d a lot lately 
It’s kind of debatable whether or not Dr. Johnny Fever still had much of a problem but there’s no doubt at all the he’d been up and down and back again on anything and everything in every possible combination for decades.
Every single person on, “Cougar Town.” If they’re not wine-ing, they will be; it’s almost like a cult.
Granny and her rheumatiz medicine?
Fort Courage on “F Troop” had a town drunk who they describe as the best in the west but he only appears briefly in a few episodes.
On “Sanford and Son” was Lamont’s friend Rollo a marijuana smoker? Fred always accused him of being a thief. I seem to remember an episode where Rollo and others find a bag and Rollo suggests rolling it in small pieces of paper and setting it on fire.
He was recovered alcoholic. And he relapsed after Diane left him. Frasier was introduced to help him get sober again. Everyone in the bar cared about his drinking.
Taco in The League.
Abbi and Ilana in Broad City.
At least one character per episode of High Maintenance.
And then there’s Rickety Cricket…
Have you considered a trial of Adderall ??
[NB: I care ;-)]
Frank will take just about any drug, and Dee and Dennis got addicted to crack. The whole crew at the bar including Mac are alcoholics, as well as Bill Ponderosa and The Waitress. Bill doesn’t seem averse to any other drugs either. And Cricket will do anything for a hit of anything.
Another possible example; Frank Gallagher in either the UK or US version of Shameless.
Mindy St. Claire on The Good Place sure did like her some cocaine, and no one seemed to think it a problem. Granted, she was already dead.
How about a real life example?
The YouTube channel BuzzFeed used to do a lot of videos of people drinking alcohol. Here’s a typical example.
Two of the people in that video, Kelsey Darragh and Curly Velasquez, have since gone public with their drinking problems.
Wow, I guess I didn’t watch the later seasons very carefully. Or my memory is not what it used to be.
It’s hard to find any show where caffeine addiction isn’t just taken for granted.
Aside from its most famous example of course.
Again, not a great fit for the OP since Zach clearly cares.
On Cobra Kai Johnny is usually shown with a Coors Banquet in his hand. It’s mentioned once or twice early on that he drinks a lot, but nobody seems to care after that.
The show is also full of consequence free drunk driving by both Johnny and Daniel. At least through season 2.