Why do you subtract cash in the enterprise value formula, and is that always accurate?

• Cash belongs on the same side of the bridge as debt, so it should be added to equity value rather than subtracted
• Cash is deducted mainly to make the resulting enterprise value look larger and the trading multiple appear cheaper
• Cash is netted out as a non-operating asset the buyer gains, but it is imperfect since some cash is operating or restricted
• Cash is netted out because it functions as a short-term liability that the acquirer will eventually have to repay
• Subtracting cash is perfectly exact in every case, since a dollar of cash always reduces the effective purchase price by exactly a dollar