The things that prevent taxes from growing to 100% in a democracy are indeed wrecking the economy, causing the tax income to decrease and the risk of losing the

The things that prevent taxes from growing to 100% in a democracy are indeed wrecking the economy, causing the tax income to decrease and the risk of losing the next election. You can argue that tax evasion is one way that may cause a decreasing tax income with the increasing tax rates but it's not the only factor.