Why is this real estate cycle different from previous real estate cycles?

In 2017, the Effective Rent Index tracked by Savills Studley started to peak in many markets in the U.S., driven by landlord concession packages rising significantly in these markets. By now, following the six- to eight-year cyclical pattern established over the last 40 years, commercial rents should have started to drop as landlords struggle to fill an oversupply of available space. Instead, effective rents have plateaued in many markets.