Similar to Oakami, I felt the need to create an account just to answer the "resistance is futile" / "all changes are good" crowd.
Saying that the horizontal-scrolling view is better is like saying that standard hard drives are better than solid state drives, that single-tasking DOS is better than Windows, or that tape storage is faster than disk. The "random access" part of RAM is important for a reason. If you have to make more relatively slow movements to get where you are going, then you are going to be slower. If you use your phone as a tool rather than a toy, you switch tasks a lot. Multi-tasking operating systems like macOS and Windows have converged around the taskbar metaphor for a reason: it provides random access of sight to all running apps. Since you could typically see 4-5 titles and partial screenshots of apps in the previous version of Android's task switcher at once, it was superior in this regard.
Change for the sake of change is also not necessarily good. Habits are important in productivity: tasks becoming automatic is how we become more capable and efficient. It's not merely a matter of weakness that people dislike or resist change. It's a matter of practicality.
At least Samsung's Good Lock app (available through Samsung Essentials) plus its Task Changer module provide some configurability. That's what I'm using until Nova Launcher hopefully makes an offering...
Android / Google / Samsung should at least provide the option of choosing how the recent apps screen will be laid out -- no one should settle for less than to have choices and control over their own devices. Simplification is bad if it also removes choice (attn: Microsoft, Apple).
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