That’s an excellent question! Allow me to elaborate.
The difficulty that the majority of explorers want in Elite can be termed as “environmental difficulties”. Hazards out and about in deep space that we would encounter while exploring. Take fuel scooping for example, the act of fuel scooping itself should be challenging, involving flying around solar flares and navigating through corona ejections and such. There could also be systems out in deep space that have intense solar storms or magnetic phenomena all throughout the system which makes exploring the system hazardous. If comets were in the game then they could be able to be deep scanned for huge payouts, but scanning them would involve flying very close in their wake requiring piloting around debris and such or risk damaging your ship. And with the added regularity of ship damage the AFMU then becomes much more necessary and frequently used, which uses ammo much faster, thus requiring explorers to land on planet surfaces much more often in order to replenish supplies. In that vein repairing the ship in deep space should be more involving too, requiring more materials than simply “AFMU ammo”, thereby forcing explorers to actually land more often and search stuff out. Simply adding module degradation over time would add more use for the AFMU with deep space exploring.
The whole process of exploring should ideally be more challenging while also being more interactive, rather than simply jumping and honking endlessly. More risks to take, more opportunities for damage, more things to do and explore, just more engaging.