That’s true. But no votes are lost in the election of a prime minister. People usually elect a party and the parties with the most votes in turn elect the prime minister (via various detours depending on the country). The prime minister is thus elected through a majority system: The party with the most votes usually provides the prime minister. Gerrymandering or something like that is therefore not necessary. In the U.S., however, the president is not elected by majority (how many votes a candidate got in total), but by electoral college, which votes according to how the majority in a state voted. This results in your vote being devalued if it does not match the majority in the state you live in. Here’s the difference: if you voted for a party to represent you, your vote would be counted even if you were in the minority in your home state. Under an electoral college system, that’s not the case: your vote is irrelevant if you’re in the minority in your home state. I can’t make sense of this other than on historical grounds: I think it used to be that elections would be held in a state and then a representative of the state, an electoral college, would ride into Washington and vote in the presidential election as the majority in the state from which he came. That doesn’t seem contemporary to me.