Corporate taxes are only 4.4% of US tax revenue[1], there's no possible way that corporate tax avoidance would make a significant difference. Especially compared to what most successful startups end up doing, which is to employ people and pay them salaries that are within the upper tax brackets. Respectfully, you seem to be trying to draw a strong connection here where it's not obvious that one exists.
You are saying that what’s left after tax optimisation is small. Not that the potential revenue if corporate benefits were taxed effectively is small. Do you have an estimate of the revenue that is declared in low-tax jurisdiction?
[1] https://taxfoundation.org/us-tax-revenue-by-tax-type-2020/