What heavy task is that? The only task that imo is demonstrably worse are the Theme and Keymap tabs which need to be re-designed imo anyway. Way too many options there and very little benefit. There is no reason to fudge around with the preferences that much in Blender.
I think this design is better overall, it follows Blender design language for parameter lists, it takes up less space than the old one, and you can easily add preference tabs to it without breaking anything. If add-on developers put their preferences in their own tabs, it won’t break anything. The problem with the old one is that you can’t add new preferences because you would need to find the space. You can’t add tabs because you would need to find the space. It was not a good design. It tied Blender into a corner when it came to preferences. Now they can just add a parameter in the list or a tab and call it a day.