Very little was thought of the military value of aircraft until the RFC's vital reconnaissance work during the BEF retreat from Mons. As late as 1912, both the Army and Admiralty were dismissive of the utility of heavier-than-air machines, although they recognised the long-anticipated potential of lighter-than-air craft - indeed, there had been numerous 'zeppelin scares' in Europe and the UK prior to the war.
On the subject of progress, the Germans in particular made huge leaps in the four years of the Great War. They took lighter-than-air craft to their logical limit, then developed strategic bombers to replace them, as well as putting all-metal aircraft into service before war's end. And they also developed pioneering tactics - the Jastas were two decades ahead of the RAF's 'Big Wings', and the 'Fire Plan' to destroy London with heavy bombers eerily predicted the strategy developed by an ex-RFC fighter pilot named Arthur Harris, which came to fruition over Hamburg 25 years later.
As an aside, Harris wasn't the only ex-RFC man to have a major influence on the course WWII - Hugh Dowding, Portal, and Sholto Douglas all learned their trade as combat pilots in the RFC, and their decisions shaped a large part of the air war in the West during WWII...