WACC and Taxes why do we use an after tax figure for cost of debt but not

Question:

WACC and Taxes why do we use an after tax figure for cost of debt but not for cost of equity?

Cost Of Debt
The cost of debt is the effective interest rate a company pays on its debts. It’s the cost of debt, such as bonds and loans, among others. The cost of debt often refers to before-tax cost of debt, which is the company's cost of debt before taking...