How can I connect a LaCie CD/DVD drive with FireWire ports to my MacBook Pro 16"?

You need this:

Apple Thunderbolt to FireWire Adapter - Apple

and maybe this:

Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter - Apple

The original Thunderbolt to FireWire adapter has a Thunderbolt 2 port. If your MacBook Pro only has Thunderbolt 3 (USB-C) ports then you need to daisy chain it off the second adapter.

> if you go the SuperDrive route a hub won't work

Clarification: an unpowered hub won't work.

The SuperDrive is powered via USB bus power (it has no external power supply).

Most unpowered hubs provide only the data connection, not the power connection to connected devices (there isn't enough power from the connection to the host system to provide full power to all downstream devices).

Powered USB hubs, though (ones that have their own power supply) typically can (and do) provide bus power to each of the USB ports and should work fine.

In theory. In practice, most powered hubs provide just the USB-A spec 500 mA of current to each port, and that's not enough for the SuperDrive. For example, when I connect my SuperDrive to a USB-A port on my Brydge/Stone Pro (powered) dock, it does not work. But connected with the adapter directly to a MacBook Pro or MacBook Air, it does.

FYI, if you go the SuperDrive route a hub won't work, you need a simple, direct USB-C-to-A adapter like the one from Apple or the one I use from nonda (Amazon link).

For the same cost as the two adapters listed above, you can get the Apple USB SuperDrive and assuming you have a USB-A-to-C adapter you can use that with a newer, USB-C only Mac.