On level ground it would be a fine way to travel with 100lbs + of gear and bulky items, kids. Not on level ground and you’re pushing a lot of weight uphill.

Basically it’s a moving truck and if you aren’t carrying a truck load why bother? If your loads are all pannier size and you’re carrying 75lbs I’d start with a bike and wheels for that load, more than that get an extrawheel trailer, more than that a cargo bike. Any of that with mtns and you’re hurting.