Sorry for all these questions, but without them answered your claim sounds like a conspiracy theory.
All governments at all levels. Ever see a government service, office, or bureau talk of an app or show a QR code? That is a carrot for those who already use and stick for those who don't. Sometimes there is a paper form you can get and sometimes not. Do you recall all those covid apps?
Why? Because the government desires to know, for a variety of reasons. The US so they can watch your small payments. Europe so they can watch your speech and carbon footprint. Used to be so they could track you if you had a 1% deadly disease.
[EDIT] Evidence? Snowden's leaks and what I mentioned already
"A Manhattan Project for online identity: A look at the White House's National Strategy for Trusted Identities in Cyberspace"
<https://web.archive.org/web/20110506083805/http://radar.orei...>
In part:
The NSTIC proposes the creation of an "identity ecosystem" online, "where individuals and organizations will be able to trust each other because they follow agreed upon standards to obtain and authenticate their digital identities." The strategy puts government in the role of a convener, verifying and certifying identity providers in a trust framework.
I'd learned about this in 2018/19 as Google+ was shutting down, through a Search Engine Journal piece (leveraging Howard's earlier article heavily), similarly only available as an archive, with the original article substituted in place with another at the same URL. This one by Kristine Schachinger:
"In Memoriam: The Rise, Fall & Death of Google Plus"
...Google was only going to be one of many identity service providers for a program run by the Federal Government called the NSTIC, or National Strategy for Trusted Identities in Cyberspace....
<https://web.archive.org/web/20181220165659/https://www.searc...>
I'll note that neither article makes a direct link to mobile phones / smartphones, but clearly as those became widespread and individually identified with a single person for the most part, use of phone numbers as unique identifiers became widespread. Indeed, on Google+, over four billion accounts were eventually compiled, those being automatically granted to every registered Android device through about 2016 (the practice stopped about then). Google increasingly required phone numbers for account registration and recovery, "bribing" G+ members with "vanity" account names if they'd supply same.[1] The use of phone numbers as account validation tokens on numerous other services is now widespread.
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Notes:
1. I resisted the bait. Ironically, the vanity names couldn't be mapped back to the 20-ish digit UUID that otherwise identified accounts, and those who did make use of the nonnumeric IDs were largely excluded from archival efforts to save G+ content when the service shut down in 2019. I managed to create at least two backups of my own (non-vain) content, for what that's worth.