Covid-19 in Québec, Canada: some observations and questions

I have some questions about Covid-19 in Québec, based on information from the following official government sites:

1. Births, deaths and marriages by month and quarter, Québec, 2010–2020 (in French only)
2. Weekly deaths by age group, Québec, 2010–2020
3. Coronavirus disease (COVID-19): Outbreak update — Canada.ca

First, some graphs of weekly deaths by age group, Québec (2010–2020)

All graphs taken from the second reference above.

Below is a graph of the deaths per CDC week for 2020 for the entire population.

Total weekly deaths, Québec, 2010–2020 — Source: Weekly deaths by age group, Québec, 2010–2020

Next, here is the graph of weekly deaths for the population aged 70 and over. We can see it follows the graph for the general population quite closely. The "first wave" is highly visible, the second wave is observable, albeit more subdued.

Source: Weekly deaths by age group, Québec, 2010–2020

The third graph shows weekly deaths for the next age group down, those between 50 and 69. Here, the first wave is sort of observable, although the numbers are much lower (check the y-axis). The second wave is not detectable (by me, at least).

Source: Weekly deaths by age group, Québec, 2010–2020

Finally, there is a graph for the rest of the population, aged 0–49. Here, if the colour-coding of the graph had gotten mixed up, frankly I would be hard put to even say which year was 2020, the year of Covid-19.

Source: Weekly deaths by age group, Québec, 2010–2020

I have Questions

1. To sum up the above, based on the records of weekly deaths for Québec, it seems the impact of Covid-19 on the 0–49 population is not really observable. The impact on the 50–69 age group was moderate at best, while the vast number of excess deaths were in the 70+ age group, and most of that during the initial wave between mid-March to June. Am I reading this right? I would like to hear more educated opinions.
2. What could have been done better? Focusing on the real impact of Covid-19 — several thousand deaths of people aged 70+ between April and June) — how much do we know about how many of these infections and subsequent deaths were caused by contagion within the general population (i.e. that could have been prevented by widespread measures such as mask-wearing, distancing, school & business closures, travel restrictions, etc.), and how many were caused by systemic problems within residences for the elderly (long-term care, assisted living, or others) resulting in intensive outbreaks? It seems we could figure this out based on the data, no?
3. Why have I not seen many discussions of Covid-19 in terms of its impact on overall mortality? (Admittedly, I avoid overdosing on media, so maybe Ive missed it.) Knowing that contagion, testing and cause of death data are all subject to major methodological issues, why are we not discussing the one data indicator that is, although lagging, almost 100% verifiable, namely: how many more people are dying compared to before?

Observations — Covid-19’s impact on mortality

1. From 2010 to 2019, the number of deaths in Quebec increased roughly 1.6% per year (the official notice at the top of the page rounds this up to 2% — they're the statisticians). Based on that, we might normally have expected close to 69,000 deaths in Quebec in 2020 without Covid-19.
2. The actual number of deaths (subject to revision of the last couple of weeks, as per the methodological notes on the same site) was 74,550. That is to say, about 5,500 more than would otherwise have been expected, or 9.5% more (10% more according to the same notice at the top of the page).
3. According to the Government of Canada Covid-19 dashboard (downloadable data), the number of Covid-19 related deaths for Quebec in 2020 was 8,226. Since we are not 8,226 above the expected number of deaths for the province, it would seem logical to infer that some Covid-19 related deaths (maybe 2–3,000) are deaths that would have otherwise occurred due to other causes.

Policy questions

Given the obvious vulnerability of the 70+ population group and the lack of mortality in the under 70 age group to this date despite widespread infection, why is the government not focusing all of its efforts and energy simply on supporting, protecting and vaccinating the elderly, while improving protocols and resources for affected residences and centres? Why are school, business and travel restrictions, not to mention curfews, still considered effective responses?

The devastating impact current measures are having on people's economic situation and on their mental health would seem to demand a better answer to these questions.