Salt is easy if you know what you are doing and have the right equipment..
That being said freshwater is more fun IMO
I have kept fish for over 35 years and have had a 'reef tank' since 1988 aprox.
I still have one reef tank ,but my interest is in my other 43 tanks.....
Breeding fish is soooo much more fun then watching species that are meant to live possibly decades or even centuries basic all die overnight....I have marine fish that are over 4 years old ,but IMO
that is still a baby...