It's more about the fact that five eyes intelligence services prefer to officially spy on each other's countries so they don't have to answer to their respective bureaucrats. They prefer plausible deniability.

Something like this:

   DC1 politically belongs to UK which "spies" on CA/US but physical servers are located in US so US ultimately retains control.

   DC2 politically belongs to France which "spies" on RUS/UKR/DE but physical servers are located in NL (e.g. in UK because one wouldn't be able to spot difference in ping). Maybe it's politically owned by UK/NZ or UK/AUS because France can't be publicly caught spying on Germany. But France wouldn't risk public arrest of Telegram CEO and the spectacle with russia if there is nothing to gain.

   DC4 politically belongs to USA which "spies" on UK/Israel but physical servers are in NL/UK

   DC5 politically belongs to UK/USA which "spies" on AUS/China/India but physical servers are in Singapore (e.g. former UK colony)

Really cool to see realpolitik mapped out like this. It also highlights the problem of metadata with these kind of topics.

The reason it's in Singapore is that Telegram can't operate in China, and Singapore-washing is the closest thing to doing it. A ton of VPNs and other services targeting mainland users but not allowed in the mainland are hosted there, it's a huge hub for companies and networks.