With HIIT it can be fun if you are playing soccer for example, that is basically hiit because if the ball is far away you are walking and when you loose the ball you run back to defend, you also run if you have a good attacking position etc. Your main point is, it’s supposed to be really fun!
Doing HIIT on a treadmill is terrible hahaha. For myself I want my exercise to have a functional purpose. Taking cones to a park and doing different drills to increase agility, speed, coordination etc like having a ball and dribbling through cones then doing walk/run sprints is way more fun for myself. I think your exercise should also be psychologically stimulating, not doing the same mundane movements every time like I see at the gym where people run on the treadmill for 40mins or use the elliptical machine. Some weeks i’ll run, play tennis once, go swimming once, ride the ubike just to mix stuff up.
Great thing about soccer, you can train/play in the rain too.