I am neither a hiker or mountain biker. My sister and brother are both hikers and have done “treks” across many trails including the JMT . My sister and her husband had many uncomfortable encounters with mountain bikes around the San Luis Obispo area while they were hiking. Most of the time the younger college aged folks were apologetic and friendly after knocking them off the narrow trail on a blind corner . Depending on the trail , I think it COULD work but most hiking trails are not set up for multi-use. As far as electric assist , I think the same applies. I ride road bikes and stay away from MUP’s for the same reason , the interaction between walkers with strollers waking 3 abreast do not mix well with cyclists , whether ebike or not.