I'd question whether time-travel, if used correctly, is a poor choice. The problem tends to be its overuse paired with the reality that it is often used badly, as a way of hitting a proverbial "reset button" to fix everything that has gone wrong previously. But as you said, Marvel is smart enough to know that time-travel needs to be done right, meaning that there must be a sacrifice involved that corresponds to the benefits it will bring. I do think the Avengers will travel through time, but I don't think it will be a cliched journey, where they just change one thing in the past to reset everything and make it all hunky-dory. There will be a catch involved, a choice that must be made in order to make everything work. I don't know what it is, but it will be a great sacrifice.
Keep in mind that the MCU has already manipulated time through the Time Stone and Dr. Strange, and they managed to do so very uniquely. I have no doubt that the Russo Brothers will be able to handle time-travel correctly, unless you're right, and they are just messing with us.