No. It takes a lot of power to close an app, it takes even more to open it up again. Doing this will reduce battery life, you're better off leaving them open, iOS has very good RAM management You should only close an app in the quick-launch screen if it is "misbehaving" - not working right, or if it is using energy (as per Settings/Battery) and you don't need it at the present time. There are several reasons you should not close apps.

I don’t close them. As far as I know, every app I’ve ever used could be suspended in the background right now.

to be honest would you have heard somewhere that it is not a good idea to close applications in the background no matter what it sounds like I have that kind of habit from android so in my case it's two or three maximum

Heck if I know. I never close an app unless it's misbehaving

probably 5 apps but i end up closing them lol

I always close my tabs but due to habit lol