Sometimes it's faster than finding the mouse cursor when clicking a link or a button (and when filling in forms with check boxes), but probably my biggest use is if I'm browsing around Google maps or Earth.
Click-drag click-drag on the trackpad is just slow and frustrating compared to just dragging the on-screen image.
I use a macbook sometimes and it's a bit infuriating when I try to drag the screen.
I don't use it constantly but I'm used to having the choice whenever I decide it's easier.
No need, you can get special teabags for hard water
https://britishfooddepot.com/yorkshire-tea-hard-water-80-pack/