A couple of things, flobbers.
Yes, it's 1.8metres, but I agree with Etch that it's probably a figure pulled out of the air.
Seriously though... if the cable is only just long enough to reach a socket, it may be in mid-air, and so could easily be tripped over etc. (Health & Safety and all that.)
Apart from that, it was a problem with the old incandescent bulbs. If one of those is tipped over, it was not uncommon for the shade to touch it and catch fire.
No such problem with modern LEDs.
The other thing is fusing. People will regularly plug into an extension lead commonly fitted with a 13Amp fuse.
Table lamps are often supplied with 0.75mm flex cable.
(Maximum current carrying capacity - 6Amps.)
Socket circuits are 32Amp. So (theoretically) the 0.75mm cable could overheat.
Having said all that, table lamps should have 3 or 5 Amp fuse in the plug so all will be well. Except that folk often replace them with a 13Amp.
Sorry about all that. I know you only asked a simple question :o)))