Still remember the first time a booster landed back in 2016.
It's extremely important to reuse the boosters as much as possible until Super Heavy is ready.
My thought is that the F9 will be used along with the Super Heavy for a long time to complete different kind of missions and loads
Crew Dragon will still be flying for several years to come, although I suspect the Falcon 9 launch cadence will slow down considerably once Starlink launches switch over to Starship.
I remember bring so hopeful when they first landed it, and were getting it back to port. Remember Elon saying something like 'it feels like the dog that caught the bus'. Seems so long ago now!