Because you get a beast of a machine for the price of MacBook Air, and because you prefer looking at a big ultrawide monitor instead of alt-tabbing like crazy on a 13" screen, and you prefer a full keyboard and a proper mouse to the cramped layout they stuff in laptops because there's no room.
Oh, and maybe a proper sound system.
And it can also double as a NAS (more physical space for storage) and home server.
Not everyone needs portability all the time. For when I do, I have a Thinkpad I can get by with, with Tailscale VPN so it has access to the workstation.
(for anyone curios, yes, it's still cheaper than top-of-the-line laptop + nas/home server combo, but my main reason is ergonomics).
Devil's advocate, but it can't if it's in Starbucks ;)
There's far cheaper workstations out there than Macbooks, especially if you're running Linux on them.
I have a VPN so all its resources are available in a Starbucks via ssh and/or RDP.
This one was a custom build with maxed ram, heaps of storage, a modest Nvidia card with as much VRAM as possible without breaking the bank, etc.. stuff I personally needed. A cheap workstation (or a much more expensive Mac) won't have that exact combo.
So aside from ergonomics, it's also customizability to my idiosyncratic wants and needs.
Laptop price disadvantage can even flip when buying used due to cheaper shipping.
Laptops can't hold as many internal devices nor the fastest parts and have worse thermals/sound though.
A desktop is both cheaper (at the same spec), while being much more durable due to being upgradable and reparable.
Sure laptop win in terms of portability, but since we can do so much on our phone, I don't really feel the need to bring a computer with me everywhere.
I do need the CPU performance, that computer is used to compile C++ code. The RAM is for local LLMs - not fast enough to be practical most of the time tbh, but I like to experiment anyway.
It certainly won't be cheap though!
I've had mine about ten years and it's still on the original CPU and mobo and PSU I think. I've probably saved a few hundred bucks from not buying another whole computer. It might not be as fast as a new laptop but it has more RAM and storage than most.
If I want to go into LLM stuff I will buy a newish used GPU for it. If the CPU is a bottleneck then I'll get a new mobo but I won't need a new chassis or PSU maybe ever. And the hard drives just rotate as I buy bigger ones
- Too small
- too loud
- too hot
- too few ports
- fake performance (good luck with your 105W "5090")
- OS confusion about active screen, keyboard and mouse (how many times have I experienced that only the built-in keyboard works during booting, or the OS showing the login screen on only the built-in screen),
- most of them have to be open or have ports in awkward places, and take up space comparable to a desktop.