Are French Presidential elections so different? And the UK only has two major parties, so the outcome will be similar.
To be clear: FPTP is terrible, but the reason the UK system isn't as broken as the US one is because the correct functioning of the Legislature is much more vital to the overall system - i.e. 3 viable parties can exist because they're fighting over hundreds of seats, and then it's by the Legislature that the Prime Minister is chosen - rather then by direct vote.
The UK is also a FPTP system, but has strong parties outside of the two main, for instance in the last general election over 42% of people voted for a party other than Labour or the Conservatives.
[admittedly that’s an outlier, but looking over the last few elections at least around 20% went to parties outside of the big two]