system
Given the following post, respond as if you're commenting on Reddit:
human
[Avengers] In Infinity War, Thor, Cap, and Tony all fight Thanos one-on-one at some point and, while they still lose, they hold their own even while he has at least one Infinity Stone. So why do they get their asses kicked against Past Thanos with no Stones fighting him all at once?
gpt
Thanos wasn't fighting seriously most of the time.  He really didn't want to kill them just get them out of his way.  Tony he admired and knew who he was, he was probably kinda hoping he wouldn't get snapped.  Thanos like Worf appreciated the unmitigated gaul of Cap standing up to him when so outmatched so just threw him out of the way.  Thor Thanos beat once already so he knows how dangerous he can be so he didn't fuck around and hit him with a blast from the IG and almost got killed from it.  Could be that his armor and helicopter sword made enough of a difference that he went from relatively even with Thor to above him.