Food and beer are the least important attractions. Those things are portable. (And SF is hardly a runaway leader in either category, even when the competition is confined to the USA.)

The main non-portable attraction is VCs and their money. People go where the money is.

The fact that SF is crowded is a feature. Your startup's recruitment pool and tech meetups and potential partners are all within a few dozen miles. If you change jobs, your commute doesn't change.

Given all that, I still don't think it's worth it, but obviously a lot of others disagree.