Through congress? There's nothing in the constitution against wages at all.
>What if the equity ends up being worth more than that? If you solve that by not paying in equity, but only cash, now you have an even bigger incentive alignment problem.
These people spend years undermining the working class and finding all sort of financial loopholes, I'm sure they can take non-cash benefits into account when drafting such a law. I don't think they will actually do so, but it's far from the realm of impossibility.
e.g. for equity: you set a similar cap on RSUs and require all full time employees to get a certain amount. a CEO can hold no more than X times the amount of RSUs as your lowest paid employee and a portion of gains in RSUs are pooled into some other system to distribute per year as an end of year bonus (remember when that was the norm?).
It's not perfect and I see two obvious holes here (contractors and part time workers), but this is from 5 minutes of brainstorming from a non-economics expert.