I don't think that such a "sweet spot" necessarily exists for every company. Many of the companies depend on these illegal business practices to be profitable.

I don't think that such a "sweet spot" necessarily exists for every company. Many of the companies depend on these illegal business practices to be profitable. If you levy fines that make those illegal practices unprofitable, there are companies that will no longer exist (and shouldn't have been allowed to exist in the first place.) The bigger problem, is that many of these companies are structured in a way that profits get extracted to the owners while liabilities don't. So even if you fine these companies out of existence, you don't necessarily make the practice unprofitable. This is why we need these fines to also pierce liability limiting corporate structures and why we need laws to allow us to put the people profiting from these illegal acts in jail.