There's nothing about eMTBs allowing people to venture in more difficult trails than with normal MTBs. Most terrains that are too hard on a normal MTB will be even harder on an eMTB because you loose some agility and the ability to carry the bike over unrideable sections.
I often see people complain about "how fast eMTBs go in some climbs, which is dangerous to bystanders". This is the most ridiculous argument, completely unrelated to eMTBs. Regardless of the terrain (uphill, downhill, flat, ...) I always slow down to ~walking speed when passing someone if the trail isn't wide enough to put at least ~1.5 meter between me and them. Meanwhile the same people who complain about eMTBs being dangerous bomb down the hill past hikers at 25+ km/h. Anyway, a long rant to basically say that any argument about speed is only ever relevant if brought up in the context of educating people to be more courteous riders regardless of the bike they ride.
Finally, you're orders of magnitudes more likely to be stranded because you punctured and forgot your repair kit (or whatever other damage to your bike that can't be fixed trailside) than due to overheating battery or whatever improbable scenario people come up to justify hating on eMTBs.