There is no doubt that the PC Parallel Port is now "legacy", but this can also mean easy access to a mountain of free used PC's and this can be an advantage in finding an easy, low-cost(likely no-cost) solution for hardware interfacing an external world circuit or MCU to a PC.
Such a machine can be used for programming, debugging MCU's, machine control, home automation, factory custom automation, to name a few applications.
In a third-world environment, such PC's control solar power, manufacturing assembly lines, etc., with the lowest possible cost and complexity.
The main 8-bit parallel data port is 5V TTL in/out, but the control handshake lines are open-collector.
To interface with 5V MCU's the parallel port provides a super stable, fast bi-directional 8-bit interface with handshake lines.
I should have said:
Parallel ports control ports feature open-collector outputs and can interface directly to 3.3V or 5V logic level systems.
Just using the control port pins allows assigning one of the pins as Clk and another as Data and by using other Control Port pins for handshaking, it is easy enough to just create your own custom fast serial channel interface to/from a target MCU.
If you Wikipedia Parallel Port:
For electronics hobbyists the parallel port is still often the easiest way to connect to an external circuit board. It is faster than the other common legacy port (serial port) and requires no serial-to-parallel converter, and requires far less interface logic and software than a USB target interface. However, Microsoft operating systems later than Windows 95/98 prevent user programs from directly writing to or reading from the LPT without additional software (kernel extensions).[9] Current CNC Milling Machines also often make use of the parallel port to directly control the machine's motors and attachments.
There is no need to fiddle around with bogus FTDI boards and shuffle through the FTDI website to only find that some drivers don't work. I have provided these already to anyone interested and they have been tested and do work.