[olliej]

The laptops were also bigger, heavier, and had less battery life. Everything is trade offs.

The https://everymac.com/systems/apple/macbook_pro/macbook-pro-u...: 2008 15" unibody [last one that didn't need at a least a screwdriver] 1" thick, 5.4lbs, 5 hours of browsing

https://www.tomsguide.com/reviews/macbook-pro-m1:M1 MacBook Pro, 0.625" thick, 3.5 lbs, 16 hours of browsing.

Obviously technology has improved (there's a 6 hour increase in battery life going from last intel laptop to an m1), but it also probably helps that that smaller light modern MacBook has a 100 watt hour battery, while the one you're referring to had a 45WHr battery.