Except the problem is that history suggests that clearly something the British did do, did matter as the British did not fall to the first puff of smoke in 1914 nor in 1939. Further but it was the difficulty of defeating Britain that seems to have been the driving force behind German strategic thinking. Look at the gamble of unlimited submarine warfare in 1917 even though it was known this would most likely bring the USA into the war and the gamble of invading the USSR in June 1941. The latter is interesting as invading the USSR was seen as the easy option compared to focusing all efforts in a campaign of attrition against the UK.
If we rather look at the proper purpose of industry which is to support a high standard of living in peacetime then again clearly the performance of British industry is none too shabby over the period indicated. Take this
study by Broadberry and Burhop at the Max Planck Institute for Research on Collective Goods who studied real wage comparisons.
Interestingly in the introduction
Recently, a broad consensus has been reached regarding the comparative performance of the
British and German economies during the second half the nineteenth century and the first half of
the twentieth century, taking labour productivity as the measure (Broadberry, 2004; Broadberry
and Burhop, 2007; 2008; Ritschl, 2008; Fremdling etal., 2007).
So far you keep saying that there is a broad consensus
At the outset, Germany lagged behind in all three main economic sectors – agriculture, industry, and services –
but its industrial labour productivity converged towards British levels at the turn of the century and hovered around
British levels until World War II (Broadberry, 1997, 1998).
But if the authors are correct then the consensus diverges from yours of arguing that the British were hopelessly amateurish failures.
The conclusion the authors draw from their study is that German comparative wages twice managed to achieve 83% of the British level in each case just prior to a World War coming along and ruining everything. Does this mean German industry is considered rubbish in the period 1871-1938? No quite the opposite, it did well in helping the average German catch up a great deal on what was at the beginning of the period "Europe’s highest wage economy" however the study does suggest that despite real and apparent flaws overall British industry was doing well by the British people.