For ease of calculation: 50% income tax and 20% capital gains, stock doubles in value.
Get paid 10M, pay 5M in tax. Buy 5M in stock which is worth 2x as much in 5 years when you sell it. Pay 5M * 20% = 1M in capital gains. Keep 9M at the end of the day.
Get paid 10M in RSUs. Sell when they vest at 2x the value in 5 years. 20M pay 50% in capital gains and keep 10M.