The movie had cringy moments, but no more than any of the hetero teen romance movie. Compare it to Everything, Everything, The Space Between Us, Midnight Sun, etc. It's no different. Cringy moments and some unrealistic situations, manufactured for drama.

You can't expect those types of movies to be "good" in the traditional sense. The movie is good because it provides representation. It showed a homosexual character that wasn't portrayed as the stereotypical gay man, that was commonly shown in the late 90s early 2000s. Maybe you, personally had trouble relating to the character. But I believe that the movie was meant more for straight audience members to relate to the character. In an attempt to make the audience care about him, and not just see him as the token gay. Just my interpretation though.

Also, just a side note, it was directed by Greg Berlanti. Who is gay. Obviously other people were involved in the creation of the movie, but it wasn't without a "queer eye".