Special relativity gives every mass in the universe its own clock. I have one, you have one, and so does every planet, but they only keep the same time if they have the same speed. General relativity adds that gravity alters time as well, so time slows down near a large mass like the earth. Hence it takes a lot of computing to make GPS navigation work because the clocks of satellites tick at a different rates depending on their altitude and speed.
How then does a large mass like the earth change time of objects around it? A virtual time ticks by as processing cycles complete, so as processing increases, it will run slower. The gravity gradient of the earth then has the effect of increasing the network load closer to earth, so it slows down our time. A clock on top of the Empire State Building then ticks faster than one at the bottom because the quantum network is running faster there.
Would we live longer on a planet with more gravity? To others it might seem so but to us, time would pass as usual. A larger planet dilates time relative to earth but the number of life events in our lifetime wouldn’t change.
Gravity is a processing gradient, so the network of space runs slower where it is stronger, which slows down time. We feel gravity as a force, see space as an extent, and experience time as life events, so it isn’t obvious why they relate as general relativity says, but if the same finite source creates them all, there will be trade-offs.