Why do we still use cable for a lot of forms of data transmission?
Wireless technology is great and can be used in all sorts of scenarios but it's complex and hard to design for. Wires are in fact superior in many ways.

( Taken from: Essentials of Short Range Wireless Standards )

With wires:


Range is not an issue - just add more cable
Latency is excellent - what goes in one end appears immediately at the other
They're transparent to data protocols and formats
Throughput is excellent
No issue with security - you know what you plug it into
Interoperability is excellent, At most, you only need to change the plug
Power consumption may be higher, but the cable can carry power
They can be specified on a single page
Topology is simple - it's typically one-to-one
Robustness to interference is generally a minor issue
Backwards compatibility is normally no more difficult than changing a plug
There's generally no license agreement, no qualification requirements and export controls