Any further explanation how it’s conspiracy theory?

Those of us that rent, or have rented, have direct experience with rent hikes far exceeding cost-of-living increases and/or inflation. I am in a much better situation now, but previously rented a location that went from 740/mo to 1100/mo over the course of two years. This was pre-pandemic in 2012 - 2014 and coincided with similar rent increases across the city.

It is a theory alleging a conspiracy. What part of that needs further explanation?

This fits the strict definition of "conspiracy theory" -- a theory that a group of people are working together in secret (or "conspiring") to achieve a specific goal.

You're attempting to apply a connotation -- that the theory is unfounded -- that is usually associated with the term, but not definitive. This is particularly troubling in the face of the evidence presented.

I believe that, in modern English parlance, the idea that the theory is unfounded is the primary meaning. I doubt the strict definition was ever considered here.