I think you've highlighted a number of issues, namely that there are differences between provinces in Canada.
A second part of the problem is primarily the changing habits of dental hygienists, largely as a result of the pandemic. Some people have decided to reduce their hours or even leave the profession altogether. As Dr. Holden pointed out earlier, right now it's a two‑ to four‑year professional training program, depending on the province. There's less pressure at the moment, but there is a shortage of staff in Canada's dental centres, even in terms of office staff.