I don't know what "horizontal" RSUs are, but they were options back then, and every year, you got a bigger (more value) pile of them. My total comp doubled without me getting a promotion in roughly 5 years.

Do you know each other or is this a judgement of character based off the few words in the above comments?

What they wrote sounds like good sense in general. A bit materialistic and generalizing perhaps, I wouldn't want a dino juice sapper and I have a lot of trouble doing pointless work let alone outright manipulative like adtech (but that's just me, evidently there's plenty on the other side), but that doesn't mean it wouldn't be generally smart to accept a 4-day work week offer for presumably a high salary in addition to starting something with a high failure chance. But we don't know about savings or aspirations or industry knowledge or investors cperciva might have had, hence it's a bit generalizing, even if it's generally sensible.