I think he produced good advertising for massively boring fields like electrostatics.
They are important to the economy. For instance, miniaturization of chips like 0201 and smaller has a electrostatic design component for the assembly machinery.
I think in the future we will see novel use of electrets as well, much like how rare earth magnets are getting into everything right now, if the right developments are made.
Also,exact knowledge of plastic behaviors for ESD and such, allowing design for cheap devices (i.e. medical field needs disposable electronics in very cheap enclosures for surgery).
Its one of those fields that IMO no one good will get into unless you interest them with that kinda silly stuff that he made.
Seriously, the classical approach to teaching that is a piff ball. A little tumble weed. Who the FUCK cares about this in physics class when they are young? The only thing it has going for it is that the parts for the experiments might be cheap.
But for ME, you think, maybe I can mod a vehicle with my knowledge. for EE you think you can build a computer gadget of some kind. For thermal engineering you might think maybe I can fix the furnace one day or build a nice fireplace. Chemistry you think oh fireworks might be fun. For electrostatics....

? I feel like the people in that one basically like.. must have gotten in there because it happened to be around and its your last chance.
But he showed us how whacky it can be and suddenly its not so whack.
The ionic lifter made IMO electostatic research from something that you can literally be beat up for talking about to something you could show joes and have them in awe. The electrostatic swamp boat on youtube right now is like... high up there on with the pop-sci audience. Who would have thought that stupid piff ball from physics class can turn into a air boat motor that is basically two steps away from a star wars land speeder with lightning bolts coming off the engine?