If corporations can just increase prices with whatever percent they need to offset some tax, why don't they just increase prices with 5% or 500% already, and po

If corporations can just increase prices with whatever percent they need to offset some tax, why don't they just increase prices with 5% or 500% already, and pocket the profit, despite there being no tax that requires the increase? Seems like an obvious thing to do, and the incentive is totally there (free profit).