When wifi was started wifi [ Version 8.02.11G ],
at that time the spepd of wifi upto 54mbps
And ethernet cable speed upto 1000mbps.
Thats why ethernet cable was fast with compare to wifi.
But now days wifi came uo with [ Version 8.02.11AC ] and the speed upto 3200mbps.
And ethernet cable speed still 1000mbps.
So now wifi is faster than ethernet cable.
Above case are in Theory perspective
If you look in theory perspective WIFI is faster
But in actual practical manner ethernet is fast
Reason :
Many things affect on WIFI (like : environment , radio waves , buildings, trees, etc.) This obstacle create in wifi .
But in LAN the possibility of obstacles are less because LAN provide internet through wire ir physical medium rather than through AIR(like : wifi )
Its general you cannot bring your LAN cable in coffee shop , you have to use WIFI to use internet .
Like its depends on you what you choose
With summarised :
-If you want to use fast internet Ethernet cable is best option .
-if you are traveller then WIFI is best .
Security perspective:
Wifi is less secured than ethernet cable ,. Because everyone can crack the encryption and they can Use your wifi and they can access your activities .
But. In case of Ethernet Lan , its secuerd than Wifi because lan is only connected to your system so no one can access your data .