Yes, England Would be Poorer Without Scotland.
Although North Sea oil gave Scots numerous well-paying positions in the next decades, many felt underpaid because the British Government kept the majority of oil income. Aberdeen does not appear to be the "Oil Capital of Europe" because many regions are quite poor. Lack of investment has plagued Aberdeen for a very long time.
It is estimated that more than £300 billion was given to the UK government between 1964 and 2016. The UK economy currently receives £35 billion from the oil and gas sector each year.
Scotland's exclusion from the UK would have significantly reduced England's wealth.