It’s twice (more than twice really) as good only at the marginal percentage ownership beyond 7%, it’s not twice as good of a deal in absolute terms. It reminds me of “buy one get one half off” - no, I’d like just one, for 25% off its list price, please. If YC revised their terms to 125K for 3.5%, that would be twice as good a deal.
Every company that applies to YC can expect to want $500k+ of capital at some point. It's extremely rare for them not to. The "no, I'd like just one" reaction doesn't make sense for a company that's aiming for a $billion+ valuation, and those are the only companies that YC accepts.
This makes sense if you wanted to sell YC 7% or more of your company. Some of us want the benefit of YC without giving up so much of our company, and the new standard deal doesn't do anything for us.