Jump is broken but not because it is a bonus action or because you can magically jump really far.
(...)
Dipping is not a big issue for now because I don't use it but what will happen at higher difficulty levels ?
Yes, jump can extend you movement by a decent amount, I don't think it is that bad - dash will still move you further and I find situations in which I don't need or wouldn't benefit from jump to be common enough, for the jump boost to become dominant strategy.
I have quite a different experience than you then. Better use jump + speed + action than wasting your entire action (and eventually extra attack) for dash.
The arena are not really large and the difference between dash and jump + speed is not really big if I remember correctly (will check in a few hours, I just broke the game).
I mostly NEVER use dash but I feel the need to spend my bonus action with jump very often just to benefit the extended movement it offer and still being able to use my action.
Jumping to extend your movement is a very optimal action if you don't have something specific to do with your bonus action.