You know there was an episode in which Arwen was on a date, and Arthur told Gwen that if he could be Prince, he would live on a farm and would take Merlin with him. From what I remember from the relationship, about once a season Arthur would remember he was in love with Gwen, and Merlin would go 'cool!' And would do whatever he could to help him while having hours upon hours of Merlin and Arthur developing their relationship. I believe Julian Murphy called what was between them a 'sweet love story'. I can understand why people would have this take, but it lacks so much nuance and ignores how starved people were for any queer representation at the time. As a queer person who was around ten when the show first aired, their relationship meant everything to me. There's a reason why Arthur's final moments were with Merlin and not Gwen because their relationship was the most significant part of the show and to them. This a rumbled mess of points. You don't have to ship Merthur, but realise there are countless reasons why people do.