That is not a given. First, it only applies to one type of equity compensation (Incentive Stock Options), other types of options do not trigger any tax upon exercise. Second, if there is a tax burden, it is only due to timing, it is not a permanent difference (is netted out when stock is sold). Third, exercising ISOs only triggers U.S. tax (AMT) if exceeding the AMT tax threshholds, which are currently very high.
That is old information. Yes, for a number of years Congress had to temporarily extend the higher AMT exemption amounts, but they became permanently inflation-indexed beginning 2013.
Also, we are in the middle of an eight-year temporary change (TCJA) that further increased AMT exemption amounts, so in fact no, it is no longer easy to hit.
"The 2017 Tax Cuts and Jobs Act (TCJA), included provisions that significantly reduced the impact of the AMT. The TCJA enacted a higher AMT exemption and a large increase in the income at which the exemption begins to phase out. It also repealed or scaled back some of the largest AMT preference items—personal exemptions, the state and local tax deduction, and miscellaneous deductions subject to the 2 percent of adjusted gross income floor—further limiting the AMT’s scope. As a result, TPC estimates that the number of AMT taxpayers fell to just 200,000 in 2018 and will remain roughly constant through 2025."[0]
ISO are generally more favorable because you dont owe regular income tax at exercise - with NSO you do owe tax on the difference between grant and FMV prices, even if you can't sell it. However, AMT does not recognize ISOs so you may owe AMT against that same difference. AMT is weird though, you can get that money back over future years by claiming tax credits
luckily, the trend seems to be to convert ISO to NSO and extend the expiration, but thats still a relatively new change and not everywhere.