Comment by rob74

I guess that's why the Space Shuttle was called the Space Shuttle: it dropped astronauts (and supplies) off at the ISS and then returned to Earth with the previous batch of astronauts (this seems to have been a typical "ISS mission": https://en.wikipedia.org/wiki/STS-105 - mission duration ~11 days; the commander, the pilot and two mission specialists flew there and back, while three mission specialists were dropped off/picked up). Whereas a Crew Dragon capsule stays attached to the ISS for as long as its crew is there, similar to (most of) the Soyuz capsules.