A couple of reasons.
An electric car from 2008 would drive 75mphish on a highway, an electric car today will also drive… 75mphish on a highway. The power demands are roughly the same because our requirements are the same so more energy means more range.
OTOH, a phone from 2008 might have drawn 3 - 5 W but phones these days are drawing 10 - 15W at peak because we want our phones to be much better. Given more energy, phones and laptops would rather aim for a battery target and use the extra power for more performance.
Also, for regulatory reasons, pretty much every laptop will top out at 99.5 WhH since any device over 100 WhH can’t be carried onto a plane.
Even despite this, battery life figures have improved over the last decade. Previously, a 3 - 4 hour battery life was considered good for laptops but now recent macbooks are pushing 10 - 20 hours. Phones used to barely limp to the end of the day but now two day phones are not hard to buy.
The TL;DR is that cars are mainly using their energy to fight basic physics and physics doesn’t change so cars basically all use the same power draw to accomplish the same tasks. Computers are converting their power into computation and there’s a lot more room to both make computation more efficient and use more computation to achieve the same tasks better so computers can target a specific battery/performance level.