We need to stop conflating a character being "relatable" with them being likable and/or a good person, and stop blaming all ills of current media trends on the former when the culprit is the latter. Because fucked up characters can and at least occasionally should be relatable.
What makes someone good is not never having an impure thought or never making a mistake; it's what we do with those negative feelings and mistakes -- and we all carry the potential for the monstrous within us. So yeah, sometimes I see a miserable piece of shit of a character and relate e.g. to his ego and selfishness because those are things I've felt and wanted to act on too and it is important and interesting to explore the places those emotions can lead within a fictional context.
Similarly, even the awful people among us, the true monsters, will often have some redeemable quality, a grace, a sliver of kindness -- which doesn't make them any less dangerous. But it does mean that a realistic fictional portrayal will capture that all too human facets of their character too. Isn't that "relatable"? Do we not lose both our moral compass and our ability to discern rl evil if we deny them that? And aren't most people a mix of the two, complicated creatures with virtues and flaws trying to do their best and often failing?
Where it all goes wrong is if you find yourself relating to a character and decide that (since you are a good person) the character then MUST be a good person too, with their flaws excused and swept under the rug. OR villainise a character for their smallest flaw and label them evil demanding only the purest of the pure souls in your narratives -- because you are a good person and a good person could never relate to 'evil'.