That’s what the employee equity is in the first place...a way for the startup to spend money it doesn’t have to get the employee. The employee, in theory or at least tech anyway, is sacrificing a better salary at an established (likely public) company to join the startup in exchange for that small chance they make it up with the equity on the backside.
Although everyone loves to pretend the US is a Captialist system...it’s not, it’s debt driven. The entire Country is premised on spending money it doesn’t have in hopes the can turn profit before it all crashes, and that is reflected in every single high-growth tech startup seeking to IPO.
Want the employees to hold on longer for benefit of investors...change the whole system and reverse the tax rates of wages and capital gains. Why should the hard working employee pay 40% of their wage to Uncle Sam while the investor who sits on their ass pays 10% so long as they can hold on for a year?