Do what brings you joy!

But if work gets difficult, should I escape and do something easier to find joy? But if there is no hardship, it's very difficult to have joy.

It's also not beneficial to only focus on the things that you like. The question is rather what's the good proportions? If 95% of my time is spent on things that are heavy, draining, and don't give me an uplifting feeling, then this is too much. But if it's 5%, you don't achieve anything extraordinary, because extraordinary stuff requires some effort and effort is always taking energy.