I am probably the only one on this forum who was unaware of this feature but on the off hand chance that at least one other person is not aware of it; I thought I would share it.
There’s an easy way to scroll built right into your keyboard: Just press the spacebar with your browser open and you’ll move down the page.
To scroll back up, press Shift + spacebar.
You can use this trick in every web browser on both Windows 10 and macOS.