Both these companies are extreme outliers (probably in the history of business!). Their outsized pay comes from their outsized profits, which comes from selling your data. I find it very ironic, that these very same people who diss startups love dissing Google and FB as being evil, but somehow when it comes salary packages they're viewed as holy institutions.
Google and FB hire very selectively, and even if you're truly qualified they may not actually have a position open for you. And most critically 99+% of engineers (including the ones in HN) probably won't make the cut for whatever reason.
Why not compare with traditional megacorps (of which there are literally (fortune) 500s of them (every company is a tech company now ;) ) like IBM, Oracle, SAP, etc? This group is far more representative of where most engineers would actually end up and hence a better comparison against startups.
Then you'd realize that startup packages don't seem that bad - or rather you're making a tradeoff between not having to deal with corporate bullshit or an extra 30K in stock grants.
Also on another note - startups are a wide spectrum (more so than megacorps). You have 3-5 person starting up startups to series D unicorn startups. Broad sweeping blanket statements comparing startups as if they're a single entity don't help too much.