In reality, the gap between Arm and x86 isn't all that big.
You are used to seeing Arm in phones, designed for power efficiency and slim profile. There are also tablets, which have more powerful Arm systems. However, batteries make up the bulk of these devices. They trick you in this respect. You are used to Arm being 'lite' and 'low profile'.
Then we have x86 systems. You are used to seeing these in desktops, that use hundreds of watts. In laptops, these can get much better efficiency. The problem is most laptops only have small batteries. x86 compilers have also evolved over a much longer time, so they are more efficient in their job. So you are used to x86 being 'bulky' and 'powerful'.
You are used to seeing Arm in phones, designed for power efficiency and slim profile. There are also tablets, which have more powerful Arm systems. However, batteries make up the bulk of these devices. They trick you in this respect. You are used to Arm being 'lite' and 'low profile'.
Then we have x86 systems. You are used to seeing these in desktops, that use hundreds of watts. In laptops, these can get much better efficiency. The problem is most laptops only have small batteries. x86 compilers have also evolved over a much longer time, so they are more efficient in their job. So you are used to x86 being 'bulky' and 'powerful'.