Astropad lets you use your iPad as a second display for your Mac, with an emphasis on functioning as a tool for artists. It used to support multiple iPad styluses but moved to only supporting the Apple Pencil.
Sidecar lets you use your iOS13 iPad as a second display for your Catalina Mac, with an emphasis on functioning as a tool for artists. I have not used it but I am pretty sure it only supports the Apple Pencil.
Both of these are sort of functioning as an alternative to buying an external monitor with pressure-sensitive stylus support, which is generally going to be more expensive than a tablet - Wacom's Cintiq line, for instance, runs from $700 for a 13-inch screen to $3300 for a 32-inch screen.
They are also in competition with the growing power of tablet apps; there's a lot of former Photoshop painters who have switched to Procreate or the tablet version of Manga Studio to get their work done.
It works fine with touch. The Pencil just allows for more precision and easier secondary actions.
I use a Mac for work - and most of user that I know don't slavishly follow the glorified press conference that Apple holds. I dare say most users don't know about most of the new features in the utility laptop they buy or are forced to use at work.