A very powerful feature in many object oriented languages is inheritance. This allows you to write a class that inherits functionality from a base class. You can then add additional functionality or override/augment existing functionality from that class with your own code often with little effort.
This is likely not a simple feature to code but I believe it would be a great asset to Hubitat if this type of feature was implemented with drivers themselves.
For example, if I have a z-wave device that did not have a dedicated driver built in to HE and the generic driver works the basic functions but does not support every feature of the z-wave device, my only choices are to live with the limited functionality or go to the trouble of writing my own by re-inventing all of the work done with the generic driver just to add a feature or two.
If Hubitat implemented driver inheritance, I could write a driver that inherited the generic z-wave driver. Then I only have to add the missing commands for the device and override the existing commands that won't do everything I need. If I needed to handle incoming data from the device, I would just have to override the parse routine to handle the data and call the base driver's parse routine passing the data my routine does not have to handle.
I can't be the first one to suggest this. I just want to plead a case for adding it as a feature.