@Intruzo exactly.
He has three/four good points, but they’re extremely important.
He’s a good guy and goes the extra mile for everyone, noticing details that other doesn’t see and/or find unimportant.
He’s a caring person and treasures others...his “plainess” is just because all of them are not flashy qualities. But Komi (who was alone when they met) and Manbagi (who was a flashy person) both have been close enough to him to come to like him.
Really glad that author didn’t pull any trick on us and made Komi say clearly that she likes Tadano, and that she’s facing Manbagi seeing her not only as a friend but probably as a love rival too.
Also, lol at Tadano having to crossedress again.