Cause for ICE, it just matters how much petrol you pump

for EV, the difference in the range is the difference whether you get stranded or not. So the number being accurate matters more, this will be less of a problem when EV chargers become more available.

Memang not accurate, that's the problem right? If not accurate, how to plan?

What if you planned based on 300km driving, but suddenly your car only can do 200km then need to charge already, and you planned to charge at around 240km, suddenly you're 40km away from nearest charger.

Charging also takes time; not like filling up petrol which only takes a few minutes. So that's also more planning required or missing your schedules due to unplanned charging required.