The primary benefit of fat tire ebike is that they're able to travel over diverse terrain, from snow to sand, better than regular bicycles. The wide tyres provide you with extra grip and traction and combined with low tyre pressure. You'll find that you're able to pedal over terrain that'd make conventional tyres sink.
All that extra wheel contact with the ground also means that you'll be able to roll over obstacles like roots or rocks with more stability, and fat bikes aren't just good for keeping steady and covering varied terrain, either. Despite the added weight, they're actually quite easy to ride uphill too. You may not be the fastest, but with traction aplenty, you should find yourself climbing at a steady pace.
It should also be noted that while fat tire ebikes were definitely designed for snow and sand, they're becoming increasingly common on regular trails too. Are you looking for professional fat tire ebike manufacturer or supplier? Saneagle can help you!