The Neptis Foundation is a Toronto-based non-partisan organization which publishes research on urban affairs. Here is its article on Intensification: what it is and what it promises.
The long-range plan for accommodating population growth in the Greater Golden Horseshoe, first created under the then Liberal government of Ontario, is still the master plan being followed by the current Conservative government. A Place to Grow - Growth Plan for the Greater Golden Horseshoe.
Done right, intensification delivers on its promise - rejuvenating urban districts and adding greatly to quality of life and property values. Here are some successes reported by the American Planning Association: 3 Zoning Success Stories.
Of course, things can go wrong. Here is a story published in the Toronto Star in November 2021: A Case Study in Failed Urban Planning.
The following article, published by Policy Options, an online Montreal-based magazine, identifies principal reasons for urban planning failure and suggests desirable process changes: The five i's of failed urban planning.