[Timothee]

One thing it can buy is time, and consequently leverage.

At Demo Day, the investors will know that all the startups have some cash to last after YC, so that they don't have to rush on the first investor that comes along which should translate to better terms for the founders. Or it could just allow them to look for investors a bit later on, hopefully providing them with a better negotiating position by having a product further along or gain some traction before needing the money.