You just have to look at it to get the right answer.
Extensibility versus portable.
The current laptops look more like tablets with a keyboard, they are thin and light and you can type and do average work.There is usually only one storage medium in it and that one storage medium needs to provide 2, 4 or more CPU kernels with data. An SSD can do this more easily than the old hard drive, which in most cases is a bottleneck for the performance of the system.
A desktop hangs in terms of better are also off the big of the closet and to what extent the closet can accommodate those things you need.An office desktop is small and compact, which is enough for an office, but not for home where you usually want some more, over time.
If you want to have all the data readily available and do not want to work with external drives, it is useful if the cabinet and the motherboard have multiple connection and space for more drives.
Of course you can buy a NAS and then suffice it with a smaller cabinet, but then it usually turns out that the NAS is running 24×7 and consumes power and is not cheap either.
Or a larger and faster video card, which usually does not fit into an office desktop.
A laptop has only one screen and sometimes you can connect an extra screen to it, directly or via a docking station, my PC has 3 screens and an Oculus Rift connected, that you do not succeed with current laptops, Gaming laptops may be excluded.
Finally, a laptop is complete right from the start and basically costs a lot of money.
A PC you can slowly build up and later decide whether you want to put a bigger motherboard or CPU, or other or more hardware in that closet, the closet misses this!
A laptop is basically a PC that is optimized for a specific way of use: it must be compact and portable and can function on its battery for as long as possible.
This means that a number of tradeoffs can be made that may be detrimental compared to a 芒 鈧?艙avere芒 鈧?PC. For instance, a laptop is more expensive, slower and less expandable.
More expensive because there are extra components in it, such as a battery, and because everything should be as compact as possible.
Slower because more speed means you consume more energy, which makes your battery drain faster and also (the biggest bottleneck) because you produce more heat that a laptop cannot drain (in addition, dissipation of heat even more energy If you need to have fans running).
Less expandable because there are usually fewer external ports on it and you also lose more of your portability when you need to drag a lot of extra parts.
Why then a laptop anyway?
Convenience.You can take it with you and use it everywhere. Therefore, you also see so many mobile phones compared to fixed.
Fast enough.Yes, a PC is faster and cheaper, but laptops are for many tasks more than fast enough.
Extensibility is becoming less of an issue.Most laptops already contain so much functionality that you do not need anything Extra芒 鈧劉 s and are also fine for a number of years.