The first few years of an engineers career should be seen as apprenticeship. The best way to quickly grow is to go work for a well-regarded, established company that will compensate them well and provide an environment for them to learn and grow rapidly. Engineers right out of school make $200k/yr working for the likes of Google or Facebook. After a few years of that, they can go try to start a company or negotiate a decent amount of equity at an early-stage startup that they believe in, and they'll have had the opportunity to actually save some money to exercise those options when the time comes.

Of course, this advice doesn't apply to unicorns which, by definition, most people are not.