I think the bee forage must have been fantastic in the 1920's judging by colony density in some apiaries from books of that time.
Aberdeen beekeeping association was huge, bigger than the whole SBA now
Honey yields were equally impressive

Perhaps those days will return but it's unlikely

It's not that farmers are less bee friendly than in the halcyon days of beekeeping.
It's that the standard mixed arable farming used in the 1940's suited the bees better
In fact pesticides used at that time could have devastating effects on the environment and bees.

Subsidies are responsible for things like oil seed rape and profit margins for potatoes and grain
Hence the farms around me rotate those 3 crops endlessly.
All these have applications of fungicide, pesticide, or seed dressings, but on the whole they are less environmentally damaging and safer for bees