There is a concept of a natural interest rate (also called a neutral interest rate, or r-star). It is the theoretical interest rate where the economy is at full employment, policy is stable (neither contractionary or expansionary), and inflation is low and stable. Basically, it is the rate needed for a good strong economy at its full potential without inflation problems.
The 2% inflation target is a decade old, it's not this historical value rooted in science. It's based on hand waving. Why does a ~20% inflation rate over a decade, and ~50% over two decades seem right? Why don't we want a lower inflationary period after a time of peak of inflation? Otherwise, as inflation is a compound effect you're still dragging the higher values with you.
Models also reflect the interests and ideas of those who create them, not just the data.The natural interest rate is a moving target over time based on many factors like monetary supply, business disruptions, etc. But, there is a given natural interest rate at any given time. The problem is that we don't understand economics well enough yet to directly calculate this natural interest rate. We can only model it and different models have slightly different results. And we all know models are based on data that is either out of date or hard to measure exactly.