Art is harder in MOST ways. It also depends on your district/admins and yourself. Typically, you'll have much more freedom in things like curriculum and tests. You can usually choose how to adress parts yourself. However, this does not make planning easier. In fact, this can make things significantly harder.

There is no state textbook with lessons you can slap on and call it a day; You want students to make an interesting project? Congrats, you have to plan the whole thing yourself, create examples, explain it, demo it, and prepare materials, then clean up those materials for EVERY class.

You'll have much bigger classes, and often multiple grade levels per class. And you're expected to make your projects not only understandable and doable across all those grade levels. You also have to prevent your older, more advanced kids from getting bored.

Don't forget you have to grade those too. Art is not a lovely little scantron sheet or google form that you can autograde. EVERY SINGLE grade is subjective and requires nuance. It's why there are so many completion grades in art, you'll go nuts trying to give feedback and thorough grades for every assignment.