Is there anything that the computer must do but the mobile phone can't?

Most of the work that computers can do can't be done by mobile phones:

At work:

CAD drawing design, Matlab data processing, drawing, Python data processing, Latex writing papers, Jade processing XRD data, GSAS, Fullprof finishing XRD, Athena, larch processing XAS data, Mnova processing NMR data, COMSOL computing finite element, SSH linked supercomputer, Origin Pro drawing.

In life:

UTorrent downloads seeds, Adobe PS processes pictures, Adobe Pr/AE processes videos, Foobar listens to lossless music, Tor browser accesses the dark net, Adobe Acrobat digitally signs, Adobe XD designs personal websites, cheats the engine to modify games, brokers process API at a higher frequency, and USB interface/card reader reads files in the camera.

Extended data:

Most things that need external devices and extended functions must be done by computers. Now the network is highly developed, and there are many quick ways to store and share files. Using CD-ROM to store data is relatively unpopular, but in some offices and sensitive files, CD-ROM is still widely used to store and transmit data.

The built-in optical drive is usually installed on a desktop computer. An external hard disk requires a power supply and a usb interface, and is usually used on a laptop or desktop computer without an external hard disk. Unlike other things that need a lot of complicated operations, such as engineering-level drawing, high-definition video clip synthesis, animation production, etc., mobile phones can't complete the above functions because of the interface and power supply. Of course, this must also be done by the computer.

In short, mobile phones are still positioned as communication tools and computers as productivity tools. These two functions complement each other, but they cannot completely replace each other.