Yup, if you just want to get to your previous app, you can do that as well. It's really a very handy shortcut, quick swipe brings the previous app, a slower swipe brings out the entire app switcher. I wonder whose brilliant idea to remove it :annoyed:
That is the one feature that made me hate the iOS 11 betas. Well, besides the gigantic font used at the top of the mail and Messages app, for example, telling me that I'm in the Mail app and the Messages app.