It seems that the command is still current, but perhaps only generates output if there is something that can be addressed.
In my case using the same Bionic Beaver as you:
chris@BeaverGNOME:~$ sudo ubuntu-drivers devices
[sudo] password for chris:
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
modalias : pci:v000010DEd00001292sv00001179sd0000FA89bc03sc02i00
vendor : NVIDIA Corporation
model : GK208M [GeForce GT 740M]
driver : nvidia-340 - distro non-free
driver : nvidia-driver-390 - distro non-free recommended
driver : xserver-xorg-video-nouveau - distro free builtin
chris@BeaverGNOME:~$
If you need to check on eg graphics drivers, you can either click on Activities at top of screen or Show Applications at bottom of screen, and it will bring up Software & Updates. Click that and then the tab 2nd from right - Additional Drivers.
Mine looks like this, and you can see I use the generic Linux driver Nouveau over nVidia (nVidia can be a PITA)
Cheers
Wizard