Yep always need to travel a speed safe for the conditions. My ebike easily cruises closer to 40 mph when I need it to. Don't do that on mixed used trails, too many dogs and kids. The motor can make you a safer rider since not as big a deal to come to a near stop if conditions warrant.
With that said I've had guys on the same trails pass my ebike on their electric skateboards like I was standing still. Those things seem insane to me, one acorn and they are airborne.