Had the UK election results been calculated in the German fashion, UKIP would have 73 seats.
But they weren’t. “First across the finish line” in the UK elections pissed off Nigel F, I remember his quite even-keel statement after the results came out. I think this is it.
http://www.theguardian.com/politics/2015/may/08/ukip-frustrated-share-vote-fails-translate-seats
In countries with many more than two political parties different methods of dealing with plurality-without-majority have been devised. Some countries have multi-part ballots (all completed on the single election day) where first choices are followed by second choices, such that the runoffs don’t have to be held separately.
If seats were not geographically linked, and candidates were elected at-large based on a threshold level of votes (either outright numbers or more likely percentages) there would still be regions or cities or neighborhoods of large cities comprised of hard-core supporters, without there being that permanent incumbency.
The UK’s old practice was a traditional assignement by geographic polity, and that’s what led to “no taxation without representation” ‘round these parts.