Composition is how I started in the music. It's the euphoric sense of making something that YOU think is the most awesome music there is because you wrote it entirely according to your taste
It also allows you to explore your abilities, challenge yourself and improve all the time.
Also, improvising and recording can be cool. Just hit the record button and improvise, later listen and see what came out best. Surprising yourself is usually a nice push to keep composing and thinking about new melodies. Maybe getting inspired by other kinds of music, like classical, for instance, to obtain new kinds of layers and melodic lines.
Hope this could be any use