Agreed. Phone numbers are now people’s de-facto UIDs. And somehow we collectively decided that Big Tech should have free access to this information to construct giant social graphs and analyze as it sees fit. Crazy sh**.
So the decline of SMS definitely has a silver lining. If each siloed messaging app uses its own UIDs, and this data stays out of people’s d** contact lists*, then in theory this is a privacy win.
What I worry about is that the OS gatekeepers, i.e. Google and Apple, will contrive to get apps like Signal and Telegram to populate the mobile contact lists with these new IDs. “So you never lose your data”, etc. Then they can keep triangulating the information and we’re back to square one.
The only failsafe solution is to ban individual users from sharing their friends’ IDs without their consent. Just as the GDPR bans websites from doing exactly the same thing. For that the EU is our only hope as usual.