Any major hospital has plenty of outpatient clinics and routine follow-up with patients. Preventative and ongoing care are a huge part of many such visits, and expanding hospital capacity is necessary to meet the growing need for this. Hospitals aren't just for inpatients on a medicine ward, the ICU, post-op surgical admits, or the ED. You want to know what would be irresponsible? Increasing our population without concomitant increases in funding to services and infrastructure, healthcare being just one example. One cannot complain about wait times and then also complain when we expand healthcare infrastructure, which obviously is going to cost money. 14 billion to construct this over how many years is really not "insane" when you compare it to our annual GDP or the government's budget. Our debt-to-GDP ratio is lower than that of the US and is comparable to most G7 countries aside from Germany (which has been very prudent with managing debt) before someone brings up debt and deficits.
Preventative care outside of hospitals has a role to play in all of this. For example, any family medicine practice has a multitude of patients who have been provided counselling and resources on how to manage diabetes through exercise and dieting. Diabetes is a great example because it costs the healthcare system so much, but the amount of resources we have put into preventative care is really quite impressive - we would almost for sure be spending more without such measures. For example, many patients are connected with dedicated diabetic educators who provide additional support on top of PCPs in management and education of DM. Physicians can also "prescribe" exercise in some jurisdictions, which can help to remove financial barriers to accessing a gym or a physiotherapist. Unfortunately, the reality is that many people do not make lasting sustainable changes to their diet, exercise, or sleep habits despite extensive counselling. It's just frankly not true that we don't meaningfully invest in preventative care. One of the best things we can do right now to up our game would be to rectify the family physician shortage.