The downside is not simply in the value of the missed taxes; it's the fact that the best business is now determined by tax evasion capability.

Instead of "the most dominant market players are the ones with the best products", we get "the most dominant market players are the ones who have some combined aptitude in product value and tax evasion". That is, some resources are wastefully diverted to tax evasion instead of to making better products.

A smart dude who could have been working towards self driving cars is instead finding ever-cleverer ways to hide money or game the tax code.