Not swiping up apps is infact better for your iPhone.
Apparently, many people keep this habit of swiping up the apps which is not useful at all.
There is a warning from experts that, there is no need quit apps by double tapping the home button and swiping up, though it is common.
It is a misconception the users of iPhone and iPad have and it is counter productive.
Users think, by quitting the apps, their phone memory and a battery would be saved, infact it is not.
More on it, the expert said “the iOS system is built with none of the above justifications which is true”
Basically, Apps in the Background are “frozen”. It is pretty good that unfreezing a frozen app uses less CPU than relaunching an app that had been force quit. It infact hurts your phone and reduces battery life as it takes longer time than usual for an app to launch after it is forced to quit”
Not swiping up saves your Battery and time.