It was confirmed relatively early on in the marketing campaign for Avengers: Infinity War that Spider-Man would join the likes of Iron Man, Doctor Strange, and Star-Lord on Titan but it turns out that things could have been very different. In an earlier draft of the screenplay, it was Anthony Mackie's Falcon who was going to Tony Stark on his trip into outer space (which would've been fun to see).
"There was one [version] where Spider-Man did not go to space, and where Falcon went to space," writer Christopher Markus says. "And it was fun, it was interesting, it’s always great to have those guys in various situations and there was a lot to do with them in both situations, but we weren’t getting as much emotion as we could if we brought them back to people who know them."
The Falcon didn't end up having the biggest role in Avengers: Infinity War and it definitely would have been a lot of fun seeing him interact with Iron Man following the events of Captain America: Civil War.
Where that would have left Spider-Man is hard to say but based on how things ultimately ended up playing out, it's fair to say the movie's writers made the right decision. What do you guys think?