It still seems like convenient, lazy writing on the MCU's part; in a critical situation like that in The Winter Soldier (where thousands around the world were marked for execution), I have to imagine Fury would have employed some back up plan to be able to reach Stark for this kind of all-or-noting situation. Moreover, from the previous movies where heroes are nowhere to be found, it might seem just as convenient that these busy heroes are all (suddenly) dropping everything to reassemble at a moment's notice for Infinity War.
Except it's arguable whether Stark is even active as Iron Man at this point (Tony confirms in Civil War that he was trying to stop at the end of IM3 and states that he started again because of the sceptre pre: AoU) and arguable whether Stark is even worth the risk of trying to contact him. He's a bit unpredictable. His performance against the Mandarin was quite bad. His family history/personal history with Shield could cloud his judgement.
And looking for problems in the setup of a movie that isn't even finished filming yet is just ridiculous. Especially since the movies you're talking about are set in a time in the MCU when the Avengers didn't stick together (Post A1, they all go their separate ways), but IW is coming on the heels of civil war which pretty clearly ended with 2 Avengers teams that seemingly were not just going to break apart.
Honestly, if there were any movie I'd be worried about in this regard in the MCU right now, it would be Ant-Man and the Wasp, since it's hard to see how Scott can have another solo adventure from where he currently is. But that would also be premature since that movie is coming after IW, so we have no idea what position he will actually be in at that point.
It doesn't, Captain Boomerang was in Central City.
Ah, I thought it was Australia. But it doesn't matter really.
He was in Gotham for both the Deadshot and Joker/Harley scenes, so not sure what you're referring to there either...
I'm referring to the fact that both Batman and the Flash are clearly active in the US and have the capability to go where they want in the US in very little time at all (we already saw the batplane in BvS).
It was initially publicly covered up as a "terrorist attack", that's even what the soldiers and the Squad were expecting when they went in. With the swirly thing in the sky, they probably had to eventually reveal the true nature of the attack.
Well, first of all the movie clearly shows civilians filming the attack before the terrorist thing even gets mentioned. Secondly, the terrorist excuse doesn't help anything. An entire US city had to be evacuated. Batman and the Flash really ought to show up, even if all they were doing was helping evacuate and rescue people.
It's the same day. The attack begins during the day, the Squad arrives in the evening.
Suicide Squad has some nonsense plotting, but they actually covered these points rather well.
The attack begins during the day. Flagg goes into Midway City with the Enchatress at night. Flagg then goes back out of Midway City and meets the Squad at the airport in broad daylight and then everyone flies back into the city at night.