Do not use "APKDownload[.]net" or "AndroidFreeApps[.]biz". Use only:
In developing markets, devices with 512MB or 1GB of RAM are still common. Running YouTube 19.x requires at least 2GB of RAM just to keep the app from being killed in the background. 8.1.0 runs smoothly on 512MB of RAM, using only 40MB of memory compared to modern versions which use 250MB+.
Note that modern YouTube functionality is highly dependent on app version. As of late 2024, users noted that YouTube app version 19.49.36 was among the last compatible with older Android 8.0/8.1, while versions 20.x and higher require Android 9.0 or later. Fixing YouTube on Old Devices: