The problem is our daily experience of how time and space operate is actually misleading. This makes it really unintuitive to conceptualise what's actually going on.

It turns out that time and space are the same thing which is called spacetime. Everything moves through this spacetime at the speed of light. There actually isn't any variation in speed of anything through spacetime. The only difference between anything is how much of their lightspeed through spacetime is specifically directed at moving through space and how much is directed at moving through time.

In order to move faster through space, you must deduct speed away from time because you have to maintain lightspeed through spacetime. This is also why you can't go faster than light. Firstly, you're already travelling at light speed through spacetime. Secondly, once you angle all of your light speed through spacetime so it's pointed at space then you have 0 angled at time and so you have no more speed to borrow from time to assign towards speed through space since you must always maintain lightspeed through spacetime.