Sorry, I was thinking about general elections.
FPTP results in a two-party system, and that is not representative of the diversity of the population. Look at what a two party system delivered for our southern neighbours.
Except it's not resulting in a two party system. If a party wants power it has to make compromises. In the USA it's representative of their population as if a candidate isn't liked they get turfed out in primaries. Perhaps that's incentive for people to get more involved at the grass roots level in nominating candidates that reflect their views