2018 also saw an uptick in the number of songs that included contrasting melodies. "The Middle" by Zedd, Maren Morris, Grey is a fantastic example of that. Particularly from a rhythm perspective, there's some nice contrast happening as we move from the verse to the pre-chorus and then into the chorus. Another song that saw its release in 2018 and is filled with some incredible contrast is Celine Dion's "Ashes" from Deadpool 2. The melody pitches change, so does the melody placement, phrase length, amount of space... Also, give Charlie Puth's "The Way I Am" a listen for the same.
Contrasting melodies make these songs feel like they're moving somewhere as they progress from section to section, which keeps people glued and interested in hearing more. If you want to work on adding more contrast to your own songs, check out how to keep your melodies interesting.