Look, the area was depleted by the Tories in the first place - catastrophically and it would seem in many ways irrevocably - and as a consequence failed really to benefit from any economic upturns the country has enjoyed subsequently. That is the REALITY on Teesside and in many other UK areas besides - no serious person disputes it, certainly if they lived through it - and that is why people of a certain age can never forgive the Tories.
What is also not in serious dispute is that when the party was obliged, post-Brexit to take account of the needs of the 'left behind' in Teesside and elsewhere, they produced a slogan, 'Leveling Up', which, while highly persuasive, was never systematic about tackling inequality. On the contrary, like all Tory boosterism, its 'policies', such as they were, followed the pattern of 'divide and rule' - just as Thatcher's flagship policies such as privatisation and council house sales had. Funds allocated under Levelling Up overwhelmingly went to areas that had returned Tory MPs - the epitome of pork barrel politics. Hence, people like Houchen get bungs, to distribute in questionable ways, but the poor of Liverpool, say, can go swivel.
By contrast, the last Labour Government at least brought in policies like Sure Start, tax credits, the minimum wage, which help alleviate countrywide, if not fully redress, the ever-widening inequality set in train by the mass de-industrialisation under Thatcher.
One more thing, at various times over the past 45 years, certain parts of the country, did benefit from economic growth some of which 'trickled down' to the working classes. However, much of that growth was essentially caused by property booms financed by cheap credit. When the taps were turned off, globally, in 2008, the underlying basis of the UK economy was shown to be fatally weak: low investment, low wage, low productivity economy in which capital had become addicted not to entrepreneurialism but to rent-seeking and profit extraction via mergers, takeovers and asset-stripping. Since then, Tory policies have revolved around ensuring one thing above all: that property price inflation was broadly maintained and with it the illusion of 'prosperity' enjoyed by anyone owning their own home - and especially by those owning more than one home. No de-industrialised working class area will ever be 'made great again' by throwing taxpayers' money at vanity airports, freeports and the like. They will be made great by providing secure homes to those locked out of the property market, and by proper state-backed targeted investment in future-proof industries and technologies.