London has long benefitted from its position allowing its working day overlapping everywhere from the US West coast to Japan, even if barely at those extremes. Most of the world's population lies between UTC-5 and UTC+5 I believe.
So if you want to be as close as possible to as many people as possible, somewhere in Myanmar would be a better choice than London.
Of course the calculus changes if you also consider how much money each of these people has access to.
“More than half of” is one of the definitions
https://english.stackexchange.com/questions/55920/is-most-eq...
I've also frequently seen "most" used to mean "a majority", though, in which case GP's use of the term is precisely consistent with the facts in their source.
That changes the equation
UTC+8 is all of China and UTC+5.5 is all of India, and in between are high population countries like Indonesia, Philippines, Vietnam, so UTC+5.5 to UTC+8 has to be included.
UTC+11 to UTC-8.5 is the Pacific Ocean and has maybe 10 million people total, while UTC+0 has >100 million in UK, Portugal and part of Western Africa so UTC+0 must be part of the range.
That only leaves the choice between UTC-1/2 and UTC+9/10. UTC-1 and UTC-2 have under a million with only a few small islands while UTC+10 has most of Papua New Guinea with 6 million.