Without Elon, SpaceX wouldn't exist (and in all likelyhood no comparable company would exist in its place), so all of it.
Without everyone but Elon, SpaceX wouldn't exist, so none of it.
Does SpaceX still need Elon? As a figure head, maybe. As a leader? More complicated, there's probably still some risky path-finding left but the biggest moon-shots are now out of the way and as long as it doesn't become a quarterly returns focused company anyone slightly bullish could probably do a good enough job.
You'd think so, but if Elon is correct in his words, some bigger moon-shots are still comping. BFR program could be interesting.
Does SpaceX still need Elon to control ownership of the company as opposed to selling to "average" investors in order to colonize mars? Almost certainly.
Does SpaceX still need Elon as the CEO as opposed to the "average" other CEO they could hire, to profitably launch satellites into space? Almost certainly not.
At least we reach theoretically answerable questions with this sort of construction, but I don't think we have enough information to answer any but the most obvious versions such as those above.
SpaceX's biggest moonshots, if they keep succeeding and Elon keeps leading, are yet to come.
There's still so much work to do.
There is no way to tell accurately when that would happen.
SpaceX is a huge collaboration of many essential individuals who's absence would have made it impossible.
And the answer is: Most of it!
Tesla is lacking a leader equivalent to Gwynne, sadly (and I'm long 100 TSLA)