Arrowverse is a TV show, there is more time to develop a romance than a movie series. The obvious answer is Arrowverse but the two should hardly be compared.
Comparing MCU Phase 1 vs the current DC films is much fair and balanced or the Arrowverse vs MCU Netflix.
It is highly impossible for a movie series to tell a romance better than a tv series of 14-22 episodes unless the TV series is very bad.