Warning! Contains spoilers for Avengers: Mech Strike #4!
Marvel confirms Doctor Strange could have easily stopped Thanos by using a horrific time-manipulation technique. The Sorcerer Supreme infamously never used the powers of the Time Stone in the fight against Thanos in Avengers: Infinity War, and though he and his fellow Avengers eventually won the day, he paid dearly for his hesitation. But a key moment in Avengers: Mech Strike #4 might as well have been written as a rebuttal to Strange's inaction in the film. Despite Strange memorably saying "There was no other way" before disappearing in a haze of dust, he was quite wrong; there was indeed another way.
In Marvel Comics, there are numerous ways one can travel through time, or even manipulate it to one's own advantage. The Time Stone, one of the six Infinity Stones, is perhaps the easiest and most succinct method; the wielder of the Time Stone can even move objects forwards and backwards through time. It's this method that a classic Avengers villain uses in Avengers: Mech Strike #4 - and though he has no need for the Time Stone itself, Doctor Strange can certainly emulate his technique, however heinous it may be.
Thanos and the Avengers' interests align in Avengers: Mech Strike #4 by Jed Mackay and Carlos Magno. The Mad Titan wishes to destroy Kang the Conquerer, and the Avengers want to undo the damage he's caused to the patchwork-of-time-periods Earth. If it were any other opponent, Thanos would obliterate them in seconds...but this is Kang, and Kang is master of seconds, days, years and more. He brutally grabs Thanos' throat and forces him to experience his entire life as the Conquerer literally ages the Mad Titan to death. Looking for all the world like a vengeful Hamlet, Kang holds aloft Thanos' skull, triumphant.
While this horrifies the other Avengers, this clearly isn't a power limited to Kang. In 2016's Doctor Strange, Stephen uses the Time Stone to age an apple forward in time, watching it rot in the span of seconds. It's logical to assume, however horrifying the implications, that Strange can use the Time Stone to force people to undergo this effect as well. Strange moved the apple forward after only practicing with the Stone for a minute - imagine what he would be capable of if he had just a little more time to hone his skills. Perhaps, during his fight with Thanos in Infinity War, he could have aged Thanos into an early (late?) grave and saved an incalculable amount of lives. This, however, would be extremely graphic and would no doubt clash with the family-friendly image Disney cultivates, even in a literal fight for all existence.
It's true that Doctor Strange looked into more than 14,000,605 different futures "...to see all possibly outcomes of the coming conflict" but evidently there were still some futures he did not see. Avengers: Mech Strike #4 ends with a dead Thanos and a team out of options - eerily similar to the beginning of Avengers: Endgame. Perhaps that needn't have happened if Doctor Strange had used the Time Stone's full powers just one film earlier.