Maybe not in terms of the outright winner who go on to form a government, but outside of that, looking at smaller parties, I think you definitely can.
The intentions of the elctorate who voted for parties outside of the big two weren’t reflected well in 2019.
FPTP is great if you want to vote for one of the two main parties, they end up quite well/accurately represented. Those who vote for smaller parties do not find their intentions well represented in the results.
Edit: actually, your initial assertion isn’t strictly accurate.
In these two post war elections the party with the most votes didn’t win the most seats. In the case of 51, Labour got more votes overall than the Conservatives and the Tories actually won a majority of seats.