Stitch with : "If there's only one timeline, then how did Doctor Strange look at 14,000,605 of them in Infinity War?"
"So: prior to the season finale of Loki, He Who Remains had been acting as the ultimate observer to enforce the Copenhagen Interpretation on the Marvel Cinematic Universe by deliberately collapsing all temporal possibilities into a single definite state that he called the Sacred Timeline. After he was murdered, reality was free to return to its natural state in which all temporal possibilities coexist simultaneously, otherwise none as the many-worlds hypothesis. Now: the Time Variance Authority only prunes timelines when they actually deviate from the Sacred Timeline, but the Time Stone enabled Doctor Strange to see how 14,000,605 different unpruned futures would unfold because those timelines had not yet manifested in a way that would have caused the TVA to interfere with them. Doctor Strange was just unaware that all but one of those timelines would eventually be eliminated by the agents of He Who Remains."