Marvel’s problem wasn’t that the films got bad. They’re actually all decent films. It’s that they got greedy. Before they thought about linking all the films, they needed to make it so all the films were great standalone films. That just made it feel like we had to commit to everything and that’s just daunting. In all honesty, films like Ant-Man and The Wasp: Quantumania and Captain America: Brave New World are decent. Though the fighting scenes were subpar in the latter. They really lack fluidity. But they suffer from the now you have to see… In short they jumped the gun and it cost them.
Also Kang was a good villain. Shame they didn’t bleed him into the universe properly. Kang versus Doom would’ve been delicious.
It’s not like there was anyone even around for that beside Strange. And they do talk about exactly that in the movie when he goes to see her. It’s handwaved away with one or two lines, sure, but they do say it, and make it clear that Strange didn’t see through the illusion until the movie and he thought she was healing and getting better and he let her in peace. It’s only in the movie that he realizes things went the complete opposite, he didn’t know the Darkhold was wrecking her up. Obviously he should have been better at that job much earlier, but they do bring it up. Strange simply doesn’t seem that good at watching over what happens on Earth (or in this dimension at all, we had that exact same joke with Thanos already). The takeaway is that Strange doesn’t check up on strong magic users around him and there’s no one other than him. Who they gonna send, Ant-Man?
That’s actually a great point about magic users. We saw what she did with the Illuminati, she probably would’ve just made mince meat out of any non magic user Avengers too. In fact, even Dr. Strange was barely a match for her. So there probably wasn’t anyone that could’ve realistically taken her on anyway.