Things Killian Jones did for Emma Swan:

• in Neverland: built her up, believed in her, and encouraged her when others called her “useless” and downplayed her strength and abilities
• after the missing year: encouraged her to believe in herself and accept her role as the savior; stayed constantly by her side showing her that she could trust people not to abandon her, made her realize she wanted to stop running
• in season 4: encouraged her further to believe in her magic; helped mend her relationship with her parents by making her understand them (and not by brushing her off as a “petulant child”); told her she was his happy ending
• in season 5A: encouraged her to fight the darkness by her own strength and free will while others tried to control her with the dagger or to use her powers to their own benefit; still tried to pull her back from the darkness back in Storybrooke, when not one of her family or supposed “friends” did as much as even try to talk to her; again proved to her that he was gonna stay by her side
• in season 6: it gets old, but again he encouraged her to believe in herself and that she could overcome and defeat anything; proved that he’d do anything in his power to never leave her alone

And those are only the things he did that impacted Emma’s character and character development. Yet, there are still people who claim Killian Jones had no other function on the show than “to stand there and look pretty”. Did they even watch the show??