NHSE was originally created to put some distance between Ministers and NHS problems as politicians were tired of always being accountable for front line problems so an autonomous body was felt to be helpful. Over time, this didn't work. The other Lansley reforms were also intended to put primary care front and centre as research showed that patients disproportionately 'trusted' GPs more than hospitals so GPs were to be put front and centre then cynically that trust was to be broken when primary care was to be further under-funded. That did succeed, unfortunately.
There developed enormous duplication and fighting between the Department and NHSE.
As an aside, when bodies in the system get 'abolished' then the activities are almost inevitably done by another body and usually by the same people (ex-PCT staff still working in the same activities years later).
As another aside, independent international research generally shows the English NHS system is relatively lightly managed and performs well when funding and the age profile of the population is taken into account)
I know health is devolved but the overall funding envelope is predominantly determined centrally and the performance of the four nations is arguably comparable with some spectacular deficiencies in NI waiting lists aside.
The main issue with the NHS performance results from long-standing under funding with periodic but unplannable increases in funding to adequate before the taps are turned down again.
Removing NHS England adminsitrative activities and integrating the duplicated activities into the Department will probably help if delivered adequately well though any savings will, at best, make a small contribution to the chronic underfunding and ageing of the population, involving and order of magnitude of £!00s of millions?
Although the most expensive care is delivered in acute hospitals at the end of life, the under-funding is probably worst in primary care - it will be interesting if any funds get preferentially directed to primary care or if it will get stuffed into acute which is differentially better funded than primary care and who, post-COVID, are increasingly shovelling inappropriate work back to primary, IME.