The word doing all the work here is "net." A net drag means the monarchy has to make democracy measurably worse than the counterfactual, and that case hasn't been made. Constitutionally, the crown's powers are ceremonial and exercised on the advice of elected ministers; the monarch signs, opens, and dissolves, but doesn't legislate. Meanwhile the cost is roughly a few pounds per person per year, far below what comparable republics spend on their non-executive heads of state. So the ledger needs an actual debit: less accountability, weaker checks, worse outcomes. My opponent has to show it, not assert it.