Tesla went with the 4680 only because it can charge faster, nothing else.
That is the biggest factor in EV,,, how fast can it recharge.
All the features that Tesla gushed about in the 4680 do indeed speak to greater current-handling characteristics. But that factor cannot come at a significant hit to energy density.
All the EV owners I've spoken to do the overwhelming majority of their charging overnight using the equivalent of a dryer outlet at home. 8 hours at the ~7.2kW you can reliably get from a dryer outlet (30A x 240V) is plenty of juice for nearly all daily driving: 57,600 Wh / 320 Wh/mi (Model S nominal, rounded up)
= 180 miles' nominal range. Given average daily driving for most falls far short of this number most will start each day at a full charge using a 'slow' 240V charger. Fast charging is first
for road trips where taking ~30 minutes to recover to ~80% is acceptable, second
for convenience charging running errands and there happens to be a fast charger nearby. There are certainly some folks who rely on fast charging for their EVs as the sole means of 'filling up', but they're presently a small minority of the EV market.
In Tesla's case, the ranges they're quoting for the Cybertruck (rumored to be the first vehicle with the 4680 cell)
don't allow for energy density that's a third of 18650/21700. Similarly, Tesla has spoken to transitioning Model 3/Y to the 4680 and there's definitely no margin to reduce capacity to a ~third and maintain the base 267- /318-mile ranges.