Preemptively posting what is people's biggest confusion:
Battery cell energy density is not the same as the whole battery pack energy density.
Western battery cell manufacturers chased the specific energy density figure, and in the process they decided to save weight on the casing, and electrodes as much as possible, resulting in very fragile battery cells.
To avoid 18650 cells being crushed, you will need a lot of structural reinforcements added to the battery pack, consuming weight.
Even with all of that, tiny, individually 18650 cells waste a lot of weight on the cell casing, on things like welds, terminals, relief valves, thermal interface material etc.
Bigger cells invariably have better casing to active material ratio, but the casing mass is still "useless.
Blade battery reverses all of above, and intentionally uses very strong, and thermally conductive case, to make the casing weight to contribute to battery pack mechanical strength.
LFP cathode feels very well at high temperatures, and has very high resistance to mechanical expansion during charge. This allows to make LFP cells much bigger than cells with other chemistries, and removes the need for liquid cooling system inside the battery pack, greatly saving weight.