VP of Engineering for Android at Google, Dave Burke, promised in a tweet that they will put Scrolling Screenshots Feature in their to-do list for Android R.
This feature is already available on OS of Xiaomi, Huawei, Samsung etc. But it is still not available on stock Android. Scrolling screenshots now planned for Android R - GSMArena.com news
Google has released the first developer preview for Android 11, the next version of its mobile operating system. It’s the earliest Google has ever done a preview like this, so the updates here aren’t that front-facing, but Google’s making some big promises, like improved support for 5G, better privacy features, and new messaging interfaces.
Also: this is really, really a preview meant for developers only — it’s just for the Pixel 2, 3, 3A, or 4, and it can only be installed with a full flash that will wipe all your data. In other words, you shouldn’t install this on your main device, unless you like using a busted phone.