Speaking from personal experience of having done a off road trips with both, but bike packing was only an over nighters. Bikepacking, less volume so forces you to pack less, arguably better weight distribution too and no need for racks or only small ones.
Also pushing a bike with panniers up a slippery slope is very difficult as your pushed out to the side so slip out a lot more when pushing and have to push in an awkward manor. However frame bags are expensive though and custom to one bike. Also if you want to chill a little more and take more stuff it's a little harder. Life is about compromises and it depends on your situation.
Speaking from personal experience of having done a off road trips with both, but bike packing was only an over nighters. Bikepacking, less volume so forces you to pack less, arguably better weight distribution too and no need for racks or only small ones.
Also pushing a bike with panniers up a slippery slope is very difficult as your pushed out to the side so slip out a lot more when pushing and have to push in an awkward manor. However frame bags are expensive though and custom to one bike. Also if you want to chill a little more and take more stuff it's a little harder. Life is about compromises and it depends on your situation.