Let's say you're Britain.
The year is 1915.
Every day, your people are bombed from above by invisible, unassailable zeppelins.
Every day, your people are bombed from below by invisible, unassailable submarines.
How quickly are you able to produce, test, and manufacture designs for cutting-edge technology which might be able to counter these threats and others like them? Is it a matter of throwing things at a wall until something sticks, or is the process more streamlined?
Is most of that prototypical technology already there by 1914, and it's just a matter of getting designs mass-produced?
How quickly are new solutions found which put old ones out of business even though they might have only come around a year or two earlier themselves? Did this happen during the Great War?
The first documented use of gas (poison) during WWI was on April 22, 1915 (Ypres). The Germans used mustard and chlorine gas against Canadian troops. By early June of 1915, the Hypo Helmet was invented as the first iteration of a 'gas mask' based on a design by Dr. Cluny MacPherson of Newfoundland. There are claims (James Bern Garner) that a working gas mask was invented in April 1915 in the U.S. shortly after the first gas attacks were reported.