Sure they have all your info. I’m not familiar with Canada but in other countries where this happens happens, the site tells you that you need to check that everything is correct, and that YOU are responsible for the information submitted. When you confirm you have effectively submitted your tax return, albeit with the help of a number of automations.

I’m in Australia now, and that how it works here too. Yes it’s just a couple of clicks for most people, but you are indeed doing your tax return.

I haven’t don’t it in Europe in a while, but that was the case when I was there (albeit less automated) and I’m pretty sure that’s the case in most countries