Another disadvantage of FPTP is the number of wasted votes. If you do not vote for the winner, your vote elects no one. Under some systems this would not be the case. Similarly, winning candidates may get far more than 50% of the votes, far more than they need to win the election and these votes are also effectively wasted.
example 1
For example, in the 2017 election, which used FPTP, the Conservative Party gained 42.4% of the national vote, while Labour gained 40% and therefore 40% of the votes were effectively wasted
point 2
However, if you compare this with the Single Transferable Vote System, very few votes are wasted. Anyone voting for a candidate who gets more than the quota required for the election has part of their vote transferred to second choices. Similarly, voters whose first choice is eliminated have their vote transferred to second option or even third choices.
example 2
For example, in the 2022 local council elections in Scotland, using the STV system, the SNP won 35% of seats on 34.1% of the first preference votes, the first preference votes demonstrating a much closer alignment of results to votes.
analysis
This clearly shows that PR systems reduce wasted votes much better than systems such as FPTP as STV offers a more equal approach by allowing vote transfers to be made ensuring that more votes are contributed to the final outcome.