

Things were definitely different to today, but I think the factors you listed are not enough to explain the massive decline in that graph.
Things like economic insecurity, cost of housing, increasing isolation / changes in living circumstances, and medication are all likely to be significant factors in my opinion.
I have an electric leaf blower, it’s pretty loud and you can definitely hear it >5m away, in fact you could probably hear it several hundred metres away. I do agree they are less disturbing overall though.