Adria and Gray served no real purpose but to be just what they were, a stand in for non binary couples. they were just poorly created and also it does not help that discovery did not really have the greatest writing.
Also the actors were bland, one note and boring as you can get. they added nothing to the show. Emperor Georgiou who we used to call Space Hitler in the hey days was kind of entertaining to watch, love or hate her, she was never boring and of course she was played by the fabulous Michelle Yeoh, who is just hard to hate in any role.
Lastly TNG has already dealt with non binary romance and had Riker of all people play one of the main characters in love with the non binary character and while it was not my favourite TNG episode, TNG executed it well as usual.
Adiria and Gray felt more like ticking a box than telling a story with depth as TNG did.
I just wish when people say ......oh people hate spock/chapel or adria/gray they give real reasons why. fans do not just wake up and start hating on a pairing, something has to trigger it.