Depends on what the definition if "good" means. Are they good characters? Good people? Are they on the side of good? What about villians? Can they be gay or black or trans and liked?
Many people will think one character is a good character while others will not so its simply down to personal preference really and if your friend can't see any examples of the argument then they really are not looking hard enough and just trying to make a problem where isn't really one.
And since whem was being any if the above only applicable to post 2010???
If acting in good faith I would assume good means character that is properly established, has flaws, has quirks and it goes together to make something worth watching.
2010 in some ways is an arbitrary cut off but in others it is a reasonable point to pick in the "muh representation" push wherein some argued* that you merely needed to have ["minority" traits] on screen and that was valuable in and of itself, with some particularly special brand of crazies going one further and proclaiming that said traits bearer having negative traits was in and of itself a bad thing which usually makes for them being a Mary Sue/Gary Stu, and super crazies further still and wanting actors that were said same to the ones to play it (because actor was not a known concept) and writers also needed to be to even stand a hope of writing them but those were generally minor enough to ignore if we are considering entertainment as a whole (though the Mary Sue types were enough to trouble some otherwise promising things. Also while fantasy and sci fi have long done reflections of current space year stuff in their fantasy world to great effect then there were a lot of super ham fisted takes on it, never mind those that also tried to do things like proclaim orcs = racist because coded some such).
*various awards shows, which in turn many producers of such things play to, also mandating that your cast, crew or some such have certain percentages of [traits] to be considered. Various investment groups also mandating things here (see ESG investment) but that is more of a company thing than pure entertainment.
Personally I would go with if you know something about the character it is because it is relevant to the story and character. Anything that is not relevant to that is wasting my time and that is a cardinal sin in story telling, even more so in film and TV when you are variously limited for time and pacing becomes even more important -- you have 40 minutes in a TV episode, taking 30 seconds to show two characters (possibly one new to the episode or minor of minor background character) with matching genitals smooching when you could be establishing your big action scene, exploring that bit more of the mystery (some of which would have been cut -- average TV show having 20-30 minutes cut for time if some things I have seen are anything to go by), unpacking more of the mystery of the main character/setting.
More generally
That for me is a master class in character outlining if nothing else and thus why you want to have it all feeding back into itself. You can tell me an interesting story about anything, [traits] (positives, negatives and interesting things falling from them) very much included within that (and amusingly for this thread most of my examples of such are probably going to be pre 2010, but that is also because that is mostly where I stopped watching films and TV in favour of internet and non fiction) and can be both minor elements, inversions** and focal points of the story. I also watch stories to show me strange new worlds, things I don't know and characters with interesting approaches to the world solving issues in ways I might appreciate as novel or effective despite not being me.
Said character also extends to world building -- a lot of things are based on history, extant religions, biology... and if your magic world has no shared history, religions or customs and maybe some alien biology to boot then why it parallels the world according to some L.A. dwelling hack writer that believed their teachers when they were told everything is all oppression, all the time (despite stats saying otherwise) then you get a bad work.
**not every black guy in the US grew up in the ghetto, ghettos are also cultures in and of themselves, ones where if you don't know the history, lingo, social mores, cues and more you might find yourself at a strong disadvantage in interactions. Having the token black guy on your team not know them can be source of amusement, two different worlds colliding and more besides. Sadly most of the time we might get a token race swap if doing an adaptation and that is not even played to.
