> Most people will be fine

this assumes majority of population has the means and discipline to purchase, register and maintain multiple pass keys and/or devices.

There's a world outside the developed countries where a typical yubikey can cost 10-20% of a family's monthly income.

A family where phones are the only tech devices in the household and the phone is typically in a 100-150 USD price range and costs about half of monthly income.

By making passkeys mandatory we are asking them to get multiple of yubikeys/phones per person in the family ?!

They cannot afford to and will not maintain multiple passkeys or backups.

Orgs will have to build a way to help them recover their accounts easily without further costs or just ignore them as "edge cases".