Many stories are told about the post war British economy. There are those who still claim that 1976 was the peak year, the gloriousness of all gloriousnesses because that was when we had the least inequality. Those who lived through it as adults are, to put it politely, less than sure that was the case.
Here's another idea though. The problems actually started in the 1930s nd it was only the 1980s that got us out of them.
The retreat from competition in the British economy was triggered by the 1930s crisis but was not fully reversed until the 1980s. Early postwar Britain was notable for cartelisation, nationalisation, weak competition policy, and protectionism.
One Nation Tories and socialists were in power thoughout that time period.
The results of the “Thatcher Experiment” in the 1980s make the case and paved the way for reversing relative economic decline. Competition was much strengthened by ongoing trade liberalisation, deregulation, and discontinuing 1970s’ industrial policy. As competition strengthened, there were major changes in industrial relations which were associated with organisational change, together with divestment and restructuring in large firms.
Despite Maggie being in the Conservative Party the best description of her economics views is "liberal". And these were liberal reforms she brought in and which had the desired effect: increased productivity.
So yes, it is Maggie wot done it.