Desktops and laptops are both similar and quite different. Quite often they can have similar hardware, the same operating systems, and comparable storage, but with each having their own unique pros and cons. In the end the deciding factor as to which is “better” comes down to what its being used for, as well as the hardware in the device.
Laptops are designed with portability in mind, and often have less powerful components to compensate for a battery installed in the device. They can be taken anywhere and allow users to do mobile creative work or anything that requires more movement. However, they are obviously less powerful in most cases, and can be much less repairable.
Desktops are more so designed for more powerful use cases and enterprise solutions. Desktops can be built by a manufacturer, but they can also be custom built by an end user. Due to the customizability of desktops, they are more repairable and upgradable and can be very versatile. However, with each desktop being different, components cannot have guaranteed compatibility with everything and that can cause issues when custom building a pc.
As for use cases, if you are gaming, you are going to want a desktop pc as you can upgrade it and have more power without worrying about power consumption or a battery. However, if you are just going to be doing office work or light creative work, you will do fine with a laptop. Again, both are equal because they have their own uses and pros and cons.