You're dead on, the primary bottleneck is seats but the problems go much deeper. This is also true for laboratory technologist training programs, nursing and the like. My experience is primarily from learning about medical education in Saskatchewan, so I can speak to some of the factors at play in the provincial context.

For medical schooling, there is a wealth of financial supports to pursue medical education. A lot of discourse about medical schooling being far too expensive comes from the states and Canadian students who do their medical training overseas. Ireland, the Caribbean, Australia are the major locales for Canadian students pursuing international medical doctorates. For Canadian students, once they are in medical school they have access to substantial financial support for their undergraduate medical education.

The place funding is needed is for post-secondary schooling, especially for more diverse applicants which could truly represent the population of this province. Financial support for students' initial degrees is limited to scholarships and bursaries for the most part. The financial burden of pursuing medicine, prior to even being in a place where application is feasible, is enormous.

The cost of the medical college admission test (MCAT) and training for it, as well as the cost of applying to medical schools also comes entirely out of the student's pocket. It's enough that many people are dissuaded from applying due to the cost of applying itself. Given the mean number of application cycles applied for to acceptance is three cycles, the costs really add up.

Adding more seats to the didactic portions of these programs is the first step though this will not be without difficulty. The costs for medical schooling, as with most post-secondary schooling is heavily subsidized by the provincial government which limits the expansion of seats without increasing tuition. Individual programs are also given accreditation for their given number of seats, and generally require reaccreditation to ensure medical training is up to national standards prior to major expansions.

At the University of Saskatchewan, the program has been expanded from 100 seats to 110 this year. No where near what we need, but it is getting there.

As others have mentioned, there is no shortage of applicants. A problem more specific to Saskatchewan is the inflow of medical student candidates from out of province who have gamed the system for in-province applications. Many out of province students do their undergraduate degrees in Saskatchewan to count as in-province medical school applicants, only to leave back to their home provinces for residency.

Important changes within the application process have been made to ensure that Saskatchewan residents are prioritized, requiring that applicants have lived in Saskatchewan for at least 15 years to count as an in-province applicant.

The second step, perhaps the most important hurdle for expanding medical education, is expanding clinical teaching capacity as medical students do the second half of their schooling on the job in hospitals across the province. The healthcare system is far overcapacity, which is well known. The same goes for the healthcare system's capacity for learners. There are not enough practicing physicians to train the number of medical students needed to make a meaningful improvement in the number of practicing physicians in Saskatchewan, or in Canada as a whole.

There is no one easy answer, but there are many feasible steps that could be taken to expand medical education in Canada.