Electronics are OK for most stuff, as long as their attentuation speed and reduced level are adequate - most seem to be.
If however shooting something like .308 from under cover, a secondary set of ear plugs underneath does help - in other words, the electronic ones do not always have the attenuation desirable for real loud stuff.
The benefit is of course yeah - they help you to hear 'normally'' between shots/shooting.
A reminder too - if studying the decibel figures .... the scale is not linear. Every 3dB is a doubling or halving of sound energy.