If Britain had an industrial base as modern as Germany, they would not be so heavily indebted after world war 1 and virtually bankrupt after world war 2, because they would be more self-sufficient. In ww2, lend lease could have been delayed, if their industry was stronger and more modern.
For example, the quantity of machine tool imported could be reduced if they had a large and advanced machinery industry like Germany. Even if the German were not blockade, they would import materials instead of machinery because they never lacked machine tool.
Besides, before World War 1, if their factories were bigger and more modern, were electrified and were equipped with advanced machine tool and assembly lines instead of using outdated steam-powered machinery from Victorian Dark Age, they could have produced even more armaments for the same amount of money spent, and the shell crisis might even butterfly away because of fewer shell defects (quality improved). They wouldn't have to place orders of millions of rifles to US manufacturers if their capacity was strong enough to produce all of them at home.
A strong precision industry = not having to import binoculars from Germany through Switzerland in 1915.
A bigger, more modern steel industry means less steel had to be imported.
Sorry, but you are mistaken. Bolding mine.
(1) Sorry, which nation was heavily indebted after WW1, and virtually bankrupt after WW2? You forget the same description applies FAR more to Germany than UK. Germany was
ruined by WW1; that great industrial base, and an economy run by generals, meant that horses were used for the army, not farms, and the Haber process was used for weapons, not fertilizer, resulting in mass hunger, directly contributing to the Kiel Mutiny and other ones, and the German High Command panicking and asking for an armistice to bring troops home to quell it.
(2) They imported materials since they lacked them, and paid for them by exporting finished good, which means a fraction of the total machine tools available has to turn around and make goods for exports to pay for the next cycle of finished goods. If Germany has twice as many tools, but has to spend 2/3 of them on making exports, then they are not that far ahead of the UK, and may even be behind the UK since the UK will buy on the open market.
(3) Even the US in the 2003 invasion of Iraq underestimated how many munitions would be used; all nations had a shell crisis. The British one was actually 2; the land one, which everyone had, and the naval one. The naval one was partly due to the British designing the the shells to detonate very shortly after impact (they emphasized how many fires the Japanese set during Tsushima), an engineering decision, made worse by the mass mobilization resulting in new people making shells and not catching mistakes (as I remember it, a British monitor had to be scuttle when a boiler combusted newspaper wadded into the neaby bulkhead (not supposed to have paper as filling) and starting a fire). The shells were resolved by 1918. And at Jutland, it was the Germans who fled, not the British.
(4) I'm sure the A-H empire and Russia, and Germany as well (since they did, actually; used long distance subs a few times to beat the blockade) would have gladly done the same, if it was possible. Mobilization meant the farmers and factory workers are now riflemen, so production falls. And while the US was great at the little stuff, even they had to buy heavier weapons from the French. Everyone heard of Lend-Lease, but there was also Reverse Lend-Lease: the British had some very nice kit the US wanted. Take a British leader from 1916 to today, and ask them British made or American made weapons, and they'll post that meme of the Mexican girl "Why not both?" British dominance of the sea coupled with strong financial reserves meant they could could do both. Germany could not.
(5) That was a decision in WW2; I doubt they imported more over peacetime levels during WW1. WW2, shipping had to be conserved, and steel is denser than iron ore, meaning per ton of shipping, it's more efficient to get steel over iron ore. Even with Europe at her feet, Germany had trouble "importing" (since was importing, but not paying for) steel from France, due to food shortages (French farms were more mechanized, so confiscating trucks and fuel restrictions meant frex, milk spoiled at farms) since coal mining is hard labor back then (need almost 3,000 calories type of work), coupled by worn down rail cars and rail tracks in Germany, directly related to the issues I raised in the other thread of how German infrastructure was run down from 1914 to 1946. Read "Wages of Destruction" Tooze will mention how many German train cars had red slips (meaning urgent work was needed), but could not be fixed due to already having a shortage of railroad cars.
Finally, you have never addressed how 1914-1919 ruined the German economy; how the Treaty of Versailles forced Germany to hand over lucrative patents like aspirin; how the hyperinflation ruined investment and savings; or how Germany suddenly cancelled its own rearmament in 1934 and 1938 to make goods for export, due to a lack of currency. I'll add another one: how could Britain beat Germany in the "battle of the wavelengths" (or something like that- long distance guidance systems/ radar) if the Germans were "light-years ahead?" (BTW, light-years ahead means to me when Europeans kill 10,000 natives to a few dozen lost, due to the massive tech gap. Germany NEVER had that sort of lead over Britain)