Interest rates have been very loose globally since 2008. Pretty much everywhere at or near zero. Far lower than anyone (c 2005) thought they could be sustained at without stimulting inflation.
What has happened globally to inflation? It is has fallen, fallen, fallen. Not just in rich countries.
Global inflation was just 2% last year. Probably the lowest since fiat currencies were introduced.
There are many reasons why this is the case, many of them speculative. But what it tells me is that the world economy seems able to tolerate "loose" monetary policy without runaway inflation anymore.
The concern about markets crashing which is popular these days, I believe, is based on higher inflation and interest rates.
As you say, for years now interest rates are rock bottom and money supply keeps increasing.
What is the reason for the years of low inflation?
Economic shocks: great recession followed by pandemic triggered huge money printing.
And bond purchasing/quantitative easing seems even more deflationary than money printing sad evidenced by Japan in 90s
Also globalisation.
Tech disruption: Uber, Amazon, grand scale websites pushing down unit costs.
Chinese manufacturing. Inexpensive, high quality goods.
Each country wants to encourage exports by devaluing currency via low interest rates.
Cheap labour supply due to migration from poorer countries to more well off countries.
There's probably other reasons I have missed.
US 10 year bond yields have risen recently to 1.6%
Much higher than say Germany or Japan. Higher than uk.
Is it high enough for stock markets to sell off?
Is it rising quickly enough to be concerned?