Over the years, some phone manufacturers have tried to go the iOS way by eliminating the app drawer from its custom UIs. Some have done things differently by keeping the app drawer but at the same time having an option to disable it for those who prefer not to have it. Most Chinese manufacturers who try to emulate what Apple does with iOS have done this over time.
Xiaomi is one such manufacturer but the company plans to do include an app drawer in the Alpha version of the MIUI Launcher. The company has just released this version which you can download and try out if you have a Xiaomi smartphone.
With the Alpha version of the MIUI Launcher, you are not just getting the app drawer but there a ton of new features including ability to change the Home screen layout as well as the icon size.
Back to the app drawer, it will not be enabled by default and you will have to enable that in the settings menu.
As mentioned, this option is available in the Alpha version of the Launcher that you can download here.