I agree. The members do believe in it. We all want to. Everyone bar the sociopaths wants a better run and fairer society for all. But those who run the party don’t believe it. They rely on the story not being examined and peddle it as true. Everyone who takes a second to think knows it’s as believable as £350m a week or that Boris was in Wetherspoons all night with a teetotal male vicar. Drinking mocktails.No, it's not lying. Most Labour members do genuinely believe that these kinds of pledges are viable, that the country is making a huge loss as a result of private companies in some industries taking extortionate profits and then avoiding paying tax on them, and that there are huge efficiency etc. gains to be made by not having private companies run those industries. You may well disagree with it (and I somewhat disagree with that, although I would still argue that a Labour Government is far, far, preferable to the shambles we have at the moment), but it's not lying.
I also wholeheartedly disagree about efficiencies. There simply won’t be any. The opposite will happen. Waste and largesse. And a lack of investment. Because we all saw the 1970s.... nothing has changed bar that the flares are now skinny jeans and designer beards (I have no love for any of the politicians. They all know the game is to say anything to get elected/keep the gravy train rolling. Then they’ll have a mandate and window to do what they like. See post-2016 for example (I am no brexiteer either, but I find the MP’s disdain for their own constituents deplorable (across the parties)).