For mouse too, actually. I grew up with scroll wheel mice so I literally never had a reason to use a scrollbar to scroll.

Yeah the scroll wheel was a big quality of life improvement when it came in. I wouldn't want to do without anymore. Though I mainly use pgup/pgdn to scroll. I wish the keyboard had a big scroll wheel. Some 90s keyboards did, like a big rod. But now if there is one it's for volume control only.

Scroll wheel tends to be quite slow compared to dragging the scrollbar for large views so they really don't replace each other.

really? what about really long pages? I frequently have to grab the thumb and because the scroll wheel takes ages

This is not true. On iOS I absolutely can grab the scroll bar and drag it around like normal. It even makes a solid click when the grab is active. It just isn’t super prominent like old desktop OSs had it.

Even as an indicator I like it larger than many places set it to by default. I am also on pretty large 27" monitors though

There are times when I'd love to have page up/down on a tablet.