It is interesting to remember that the air war started with reconnaissance aircraft. A typical recon aircraft of 1914 was the Blériot XI:
This aircraft was little more than an engine bound to wings by a frame. The photographer/observer was seated behind the plot and pointed his camera alongside the fuselage.
It was not long until someone figured out that denying the enemy reconnaissance data was a good idea; and thus was born the fighter aircraft.
This excellent BBC documentary documents the air war in WW1. It contains some wonderful footage.
https://youtu.be/3axANcTlhIE
Aircraft development was rapid. Advancements in armament, engines, and aerodynamics made the aircraft of 1918 vastly different from those of 1914.
The symmetry and simplicity of the early Nieuports:
The streamlined Albatros D series, here a D3:
Culminating in the birds of 1918. The Fokker Dr1:
The Spad 13:
The Sopwith Camel:
These are all aircraft of the first 20 years of flight; add another 20 years and jets will be fighting the air war.