Of course EU regulations, contrary to the US, limit pedal-assist bikes to a maximum continuous rated power of no more than 250 W and a speed to 25 km/h before cutting out power, leaving you to rely your legs for more speed.
It is plenty, as long as the torque is sufficient. When mountainbiking I have never felt I would need more power, even on climbs where keeping the front wheel down is tricky. Of course you cannot sustain 25 km/h on steeper hills, but do you even need to?
I can and need to with my American bike with a 45kmh limit and 250/750 peak. I used that bike for a daily 50km commute big hills all the way to the foothill. If it weren’t for that setup I would have had to drive everyday.
Perhaps if Europe stopped getting in their own way over ebike limits more people there could abandon their cars, at least for some of the time?