On-screen volume control

[HubKing]

Is your feature request related to a problem? Please describe.
I'm always frustrated when I have to press hardware volume buttons multiple times to adjust the volume, especially on a tablet, and especially when the tablet is laid on a surface. The buttons are simply difficult to press and impossible when a tablet is laid on a surface.

Describe the solution you'd like
iPad has on-screen system volume slider, unlike Android, and its Music app also has on-screen volume slider. On-screen volume sliders are a lot easier and quicker to adjust. On a Android tablet, a lot of screen space is wasted anyway, so why not add a volume slider? On Android devices with limited screen space, Musicolet has a volume button that shows a volume slider. I think that will do.

On-screen volume slider has an additional benefit: I can verify the current volume visually, before starting playing a song. Am I the only one who started playing a song on a music player app and get ones ears blasted by the loud sound because I had set the audio volume to the maximum because of low-volume YouTube videos?

Describe alternatives you've considered
No alternative. Audio volume slider is the only way.

Additional context
Refer to these.

Apple Music on iPhone

Apple Music on iPad

Apple Music on lock screen

Musicolet Android app (notice the volume button icon)