Thanos caught everyone off-guard in Infinity War. The opening of the movie was a blitz that killed a bunch of Asgardians and wounded many more, followed almost immediately by an invasion on Earth. There wasn't enough time for Strange to coordinate with other sorcerers (he didn't open all those portals by himself) by the time he knew where Thanos was.
Thanos was too powerful. Thanos already had the Power and Space stones at his command by the time Dr. Strange became aware of the invasion. And by the time Strange knew where to go to fight him, he'd also collected the Reality and Soul stones (the latter of which was able to dispel all of Strange's enchantments in Infinity War).
It wasn't that short. The resurrection is the first in a sequence of many events. Thanos invades shortly afterward, but then, after remarking that arrogance is foolish, he decides to sit there and wait for Cap'n America to wake up so they can fight. The tres amigos battle and stall for several minutes as well -- plenty of time, presumably, for Strange to explain the situation to his fellow sorcerers, and for them to recruit forces to fight Thanos. It helps that most of the fallen would've reappeared in Wakanda or New Asgard, already grouped up and ready for battle.
In the final battle, Thanos is far weaker than his Infinity War incarnation. He is four years less experienced, doesn't have any Infinity Stone powers, and only has the forces he was able to gather at the time checkpoint Nebula brought him from, plus maybe any loyalists that happened to still be near Earth in 2023. His Death Star is taken out of play relatively quickly by Captain Marvel, who was "busy" during Infinity War. And he still comes extremely close to winning.
Strange presumably just had to wait for these exact circumstances to arise, otherwise nothing he did would've been enough.
A lot of these types of questions are probably going to get closed as "primarily opinion based" or something, but in case this one isn't, I gave it a shot.