When you’re first starting out, ear training can seem like a strange and pointless activity. If you are studying just to pass an exam (e.g. the “aural skills” section of ABRSM instrument exams, or your music college’s ear training final) then you can easily get bored and frustrated with your ear training progress.
Fortunately, ear training does get easier.
The more you do it the better you get
In a way, it’s as simple as that. You do need to pay attention to the way you approach ear training, and stay true to your musical goals for it to be rewarding. But as long as you are training in the right way you will see continual improvement, and what was once very challenging will become instinctive.
This is probably the best reward from persisting with ear training: you start to feel more “naturally” musical as the ear training lessons become truly ingrained in your musicality.