That’s totaly two different problems.
PS4 controllers (and all recent controllers) are built around USB and Bluetooth standards. This is more about finding the correct key/encryption to keep the device connected rather than emulate a physical hardware.
For the Sega/Megadrive this is quite different: they weren’t build around any protocol. All the other controllers used classic encoders or were somehow reverse ingeneered at some extend, but even though all functions weren’t supported (as exemple, there’s no Dreamcast VMU support)
The 3 buttons controller is easy to duplicate (it’s a simple 74LS157 multiplexer), but the 6 buttons Genesis used a really weird pulse signal which is insert between the regular button. It’s even more complex to analyze and decode it (this is a subject which comes back frequently on arcade/supergun forums)
This is a control so weird that even some games have some issue with it on the original hardware (like Golden Axe 3) and Sega put the “mode” button to set the controller in classic 3 buttons mode.
Why do think Toodles never put it on the Mc Chtulu after all this time?