This chart of working age population growth explains the economic growth , inflation, and rates well to me.
In 1970s, high working age population growth, leads to high consumer demand growth, creates high inflation , leads to high nominal GDP growth and rising rates.
All that Reverses course in the 1980s, lower pop growth, lowering demand growth, lowering inflation, lowering nominal GDP growth, lowering rates.
Then working age pop growth remains very low from GFC to now (except illegal immigration blip), hence generally low and stable rates.
Going forward working age population growth is almost zero, which is why I see rates eventually falling substantially.