I wish I had a job where if I completed all my work quickly, I was allowed to do whatever
My last boss told me essentially (paraphrasing), "I budget time for your tasks. If you finish late, I look like I underestimate time required, or you're not up to it. If you finish early, I look like I overestimate. If I give you a week to do something, I don't care if you finish in 5 minutes, don't give it to me until the week is up unless you want something else to do."
We certainly did not receive bonuses based on doing work faster, so unless you are, what incentives are you being driven by to do the work sooner?