Well, the fact that Bell Labs is/was an actual real thing, whereas YCR currently consists of good intentions and an amount of money which, while very generous on Sam's part, would fund a Bell Labs size organisation for a couple of days.

Track record of results, corporate memory, facilities, and the collective wisdom and experience of the fellows.

YCR could be the same, one day. Nevertheless, it's a very long and perilous road from YCR the proposal, to Bell Labs 2.0.