EVs are less efficient at high speeds, so there's more to be gained by improving aerodynamics. ICEs would gain more by improving stop-and-go efficiency.

There's at least two different issues in your question:

- the economic cycle (regular repeating of periods of growth and recession) is caused mostly by debt; when interest rates are low the economy can grow on credit, but as the amount of debt grows so does the risk for lenders, who will in turn demand higher interest rates if they are to take on more credit, which slows down the economy until risk goes back down, repeat. In this sense, recessions are "beneficial" in that they are needed adjustments to over-leverage.

- Since the industrial revolution there has been a long term growth trend driven by technological innovation, basically improvements in our ability to do more with less, even once you cancel out the short-term debt-driven booms and busts. Economists tend to project this trend into the future indefinitely, but - and this is just my opinion - future innovation is not guaranteed, and the period since the industrial revolution is a giant anomaly in the larger historical context. It is true though that our societies absolutely require this type of growth; without it, the only way for any business to succeed is at the expense of some other business.