Generally speaking, the equity you receive (in whatever form) will effectively only reflect increases to the company valuation.
In the case of options, if you get 1% of a $100M-valued company, it is worth $0 if the company value stays <=$100M, and will only be worth $1M if the company value increases to $200M.
In the case of RSUs, if you get 1% of a $100M-valued company, you are taxed as if you were just gifted $1M (pay 35% to Uncle sam today, and a few more % to uncle state as well), although you can't do anything with it, and if you forfeit it (because you're fired or quit or the company folds) you can't get the tax back. However, if the company does get to $200M valuation, and you manage to sell your equity, you'll get $2M in proceeds and only be taxed on the $1M increase this time.