You are the one riding the bike so go with whatever your taste and budget allows.
My own experience ranges from panniers to seat pack and bar roll to (most recently) Tailfin aero pack and fork bags.
Panniers hold the most stuff but are bulky and can easily be caught on undergrowth, branches and fences on narrow tracks and trails.
Seat pack and roll bar is good for distributing weight and keeping the width of the load down but can be awkward to pack and require careful planning to get things in in the right order.
Tailfin is bloody expensive but very good. It’s really a rethink and combination of panniers and packs that makes for a solid set up with no sway or bounce, and that is very welcome when riding off-road.
The Tailfin gear has made my seat pack and bar roll redundant I think but I will still use panniers for longer road-based trips due to their extra capacity and ease of transporting between bike and house/tent/hotel.