> What this does is, it collects money from today's FAANGs while disincentivizing future startups from starting here.
Does it? Startups probably start out with a fairly small Executive Pay Ratio because they start out without a lot of low-paid grunts, and its already not common for them to open satellite facilities or move HQs for grunt work when they scale out to more jobs where they aren't trying to attract locally-concentrated elite talent. Because its triggered on the ratio between the highest paid managerial employee anywere in the firm and the median pay of employees in the City, it really just adds further incentives to do low-level gruntwork outside of the city, but doesn't seem otherwise to really change the structural incentives much for startups.
OTOH, it does make it more expensive for any widespread organization whose headquarters and elite labor are elsewhere to operate a facility with mostly low-level labor in the City; a tech startup headquartered in the City might never be hit by it even as they scaled up if they are focussed on automation, as they might never have a low-paid workforce. OTOH, retail, etc., outlets, hotels, etc., of firms with highly-paid executives with their main executive and high-paid labor force outside of the city would be hit hard (as far as compared to other firms, I don't think the tax rate is ever high enough to really be "hit hard") by it on their operations in the City.