Why is Churchill hold in such reverence?
Probably because the allies won war the war as they were always going to.
Churchill was at his peak just before the First World War when he and Lloyd George were formidable adversaries. He was in fact as radical as Lloyd George, He actually advocated Keynesian policies before anyone had heard of them in Opposition but like Lloyd George quickly came into line with discredited classical economic policies when in government. ( From the end of WW! and the start of the Great Depression UK GDP per capita fell!
He was a very good cabinet minister BEFORE becoming first Lord of the Admiralty. Unlike Lloyd George he was quite emotional ( and not a philanderer) and it was because of this the Gallipolli campaign became unstuck.
He was a disastrous Chancellor of the Exchequer and then went to be an embarrassing backbencher.
He saw immediately the political advantages of exaggerating of Hitler and the eventually he came back into cabinet.
His disastrous foray into Scandinavia was somehow forgotten.
What people forget is two things when talking about Britain against Germany.
Firstly as Adam Tooze shows in The Wages of Destruction Germany were Never going to win a world war. Indeed they only 'beat France because everything went right. Against the Soviet Union when they did not they got 'beaten.
In retrospect and even at the time ( Roosevelt was advised so) it would have been better not to help the Soviet Union and just let it and Germany fight it out until no-one was left standing and then 'change' both countries.
Secondly as Bonhoeffer tried to change through his british christian network but failed
Churchill said every German was a nazi thereby prolonging the war as the Germans who saw Hitler for what he was gained no support nor resources from overseas.
After the war Churchill was terrible .He stayed to long, had nothing to offer, fell asleep in cabinet meetings and left Eden to become Prime Minister way too late.
He had no ideology and so did not get rid off Labour's disastrous nationalisation programs.