Power balances inside those coalitions (which can vary wildly depending on the votes outcome, compared to two party system) affect a lot. If the stricter left-wing party wins over the center-left party and gets to be the PM party then obviously the coalition is going to be more left-wing. And so on.
And it offers much better options for people to shop for a party they actually agree with. Having to vote either this or that is a sucky system because it offers basically two avenues for you if you are not happy with the party you voted for. Either you switch to the other side totally (which is often not at all what you want) or you don’t vote and you’ll just end up helping the other party anyway. Great options.