On: SpaceX catches the Starship to end Flight 15

Manned missions have totally required an escape system of some sort. So when you know the rocket isn't going to make it, you can let the crew escape.

In it's current design, there's no way to do that. Which is also why starship can be a lander on the moon, but it's crew will board after it gets to orbit (for now, at least).

If there are multiple startships in orbit, that can provide redundancy for manned flights.

The Shuttle didn’t have an escape system.