I found this article enlightening (https://www.cbc.ca/news/health/canada-reopening-covid-19-delta-variant-1.6087003). It looks at how infectious disease experts are split over whether we should be concerned about opening up too fast with the Delta variant. There are numerous links in the article pointing to other articles. It's quite a balanced look.
I was quite surprised to learn that the reproduction rate of the Delta variant is still above 1 in Ontario, meaning it's still spreading. It already makes up 70% of cases. As Delta now makes up the majority of cases and the vaccines are less effective against it, can we avoid a fourth wave? As if to highlight the concern, the Science Table (Ontario COVID-19 advisory panel) subtitles its Dashboard (https://covid19-sciencetable.ca/ontario-dashboard/) with "The Race Against Delta."