Keep in mind that it’s $30k the first year. If you get the same bonus the next year, it’s now $60k ($30k from the first grant + $30k from the second). At 4 years you’re now making $120k per year above your salary. On top of that, Apple stock has been doing pretty well for something like 15-20 years now. If you don’t immediately sell, that first $30k you got is now worth significantly more, though there are no guarantees that will continue into the future. But it certainly can work out very nicely. If you start over at a new company, you lose that extra $120k per year for the next 4 years until you’re vested at the new company.