Clickup's native time tracking would be amazing if it integrated with the calendar functionality. Being able to plan your day within the calendar and then log a task and the hours you had associated to it as complete with a single click. Boom, Clickup would then have super powers!
Streamtime does this incredibly well with a simple to do/done dragable dashboard for the weekly calendar. But I think the Calendar functionality as it is could easily implement this with a button associated to the . Clickup, you can do it!