Answering your question in good faith, though it seems obvious to me: people prefer laptops because they are portable. You can work from home, or the train, or another city, or a meeting room.

By the way, it is possible to connect a laptop to whatever monitors and keyboard you want

> why on Earth people would prefer laptops over large dual monitors, full sized keyboards, ... and so much better performance and cost effectiveness.

I think I'd struggle to bring that around meeting rooms all day. I have a monitor and keyboard to plug in on my desk, of course...

The reason is obviously portability. People like the ability to take their entire development workstation wherever they please, or perhaps to even sit on a sofa or bed.

I’m not sure why you’d need that explained.

For me it's because it's what the business mandates. I have a docking station so I still have two big monitors (three if I want to keep the laptop open) and a mechanical keyboard, but the business wants me to use a laptop because it can be locked away after work, it can be brought home for home working or on call, and it's part of the disaster recovery plan should the office become unusable.

Because a laptop is possible to carry with you when you go places, and a desktop is not.

Laptops can be carried to meetings, so you always have your whole setup with you, and they make it easier to do work someplace other than your desk.