Question
In a piece of the script from Spider-Man: No Way Home, it explains how Wong becomes Sorcerer Supreme, since Doctor Strange blipped. However, I don't think it is explained why Doctor Strange becomes Sorcerer Supreme, after The Ancient One dies; he was only a student for (around) a year, when other sorcerers like Wong and Mordo have been sorcerers for (perhaps?) years...
DR. STRANGE: “Higher duties?!”
WONG: The Sorcerer Supreme has higher duties, yes.
PETER (to Dr. Strange): Wait, I thought you were the Sorcerer Supreme--
DR. STRANGE: No, he got it on a technicality ‘cause I blipped for five years.
PETER: Oh. (to Wong) Well, congratulations.
Answer
Stephen Strange was never named (in the MCU) as the Sorceror Supreme
It's clear that he might have been awarded the title (the Ancient One suggested that Strange was "the best of us" but due to the Blip, this title went to Wong.
Frankly, it seems to a title without much benefit since Strange can do anything Wong can do (it seems) and ignores Wong's instructions whenever he feels like it.
Answered By - Paulie_D