A couple of things to remember.
Thunderbolt,
you can daisy chain multiple devices together.
Charging iPhone/iPad/ Magic Keyboard, Magic Mouse,
Don't buy the usb-c to lightning adapter, just get a usb-c to usb adapter.
Not only is it cheaper, but you can temp connect a device to it, and then use it for say a usb3 external hard drive.
Some external thunderbolt monitors, like that 5k LG one, come with usb-c ports on the back, and it can charge your macbook i believe. So you can wallsocket>monitor>3x usb hard devices>connect to usb-c on macbook pro and you have 3 ports free, and already 4 devices connected + charging laptop.
Printer,
most printers support wifi these days.
NAS, backups,
some routers now have usb3 port on it for backups or printers, and with ac wifi it's not slow.
some routers dont' use all ethernet ports, if you have media to store, or backups, consider a nas over ethernet, great for mass storage in reliable raid setups with redundancy.
Could you also connect speakers via the USB-C output on the back of that LG monitor? Looking for that single-cable solution.