I can kinda see the use as a semi uplift replacement, but you are stuck with a fat heavy bike on the way down again. I’m a bit of a crap descender, but even i can appreciate how much more agile a light bike is to pop off roots etc.
As for the 30% further thing, i’d choose a carbon hardtail with ralphs rather than a 48lb bike with dragtastic tyres on.
Guess it kinda depends what biking is to you. If its a way to access the great outdoors and you really want to see more, then by all means get yourself an e-bike. If however its the feeling of riding the bike, the popping of roots, the burst of power to clear a tricky technical climb etc, then stick with a real bike.