[Maken]

>deprecate usted to avoid the social awkwardness of using the wrong level of formality

I'm Spanish and I think it has been months since I have heard "usted". When you are writing to someone you are not very familiar and you want to sound more formal the way to go is to use a "implicit usted", which means you refer to the other person by name but use the third instead of the second person. Anyway, better avoid using "usted" directly, it sounds awkward in almost any situation.

[Turing_Machine]

'I'm Spanish and I think it has been months since I have heard "usted".'

This varies a lot between different Spanish-speaking countries. Heck, in Argentina they still use "vos".

[Maken]

But that's different, because in Argentina they have replaced the second person and "tú" by the third person and "vos". For them it's not a formal addressing at all.

However, I won't deny that for most Spanish-speakers Argentinians sound surprisingly polite.