How exactly is it different from just freeze your asset/account and you can't take cash out of ATM again? I mean the shut you down part. Okay, that's do a situation check.

• say I am some activist protest and is PITA to some gov official, and he wants to make my digital wallet not usable with my government verifiable method.
• I found out either I can't use the service I was using or say the money is gone, then talk with lawyers backing my org.(maybe others in the same/similar org will run into it as well.)
• pile up the case and evidence then go check directly with the bank about why the service not working(either directly with BoC or other down stream banks, depending on how that service is implemented)
• bank, like freeze asset might tell you you have court order or something that freeze your account from withdrawing. someone has to give the order and press the switch to block your service.
• now you have the upper gov level to inquiry, file law suit or Freedom of Information request. Just find out who give the order to cut you off from financial system.
• make some news and see the distrust destroying their control over night/week. Whoever push to cut you off to make you example off will deal more damage to the entire economical system than damage to you.
• It's not China here.

As with anything in financial, the only way to prevent bank runs is "trust" that when I want to use my tokens/bills/whatever other format, it's there and nothing is changed. It was tried and true pretty much through out the history with currency not actually mint from valuable stuff(gold/silver/etc). In fact, for some regiment change to combat corruption, a very good way is to issue new bills and expire the old ones. A good standing citizen where most of their asset in trackable source(bank, liquid cash) can simply just deposit and exchange with new bills. The corrupt hoarding actual cash will have hard time to exchange or declare where the huge pile of cash is coming from. that's why more "modern" corrupt usually convert to other stable foreign currency, and why modern money laundry network(between countries) is forming to try deal with those. It's also why you have to declare cash or things of value exceed threshold when you enter Canada.

A full digital approach would cut a lot of cost from our financial system and make a lot of things accountable. It can be issued as a format like prepaid visa card for foreigner visit temporary so there are no privacy issues. You can't use them to purchase outside Canada anyway.

So tell me what other concerns you have regarding not having cash?