I am not sure what you mean by a hard wallet. A web search just reveals hardware wallets. If you mean those: they aren't even necessarily needed. No government can 100% control or block the software you download and run onto your computer (which is needed even when using a hardware wallet anyway), especially since you can use Tor and Torrents to get it, in case they restrict internet access. They can forbid the usage, but actually effectively preventing it is a different story.
An example, where a currency other than the national currency is used, already exists. Actually a few:
The U.S. dollar is also widely used throughout the world as a quasi-currency of exchange. While it should be no surprise that the U.S. dollar is widely accepted for commerce in both Canada and Mexico, the U.S. dollar is also accepted in a host of tourist destinations including the Bahamas, Barbados, Bermuda, the Cayman Islands, Sint Maarten, St Kitts and Nevis, the ABC Islands of Aruba, Bonaire, Curacao, and the BES Islands including Bonaire, Sint Eustatius, and Saba—now collectively known as the Caribbean Netherlands.
If I remember correctly there are even countries where using U.S. Dollar is forbidden, but since the national currency devaluates so much, everyone still uses it.
Personally, I'm sure if cash is retired and CBDCs are forced to be used in EU / USA for maximum surveillance, people will easily be able to instead use Bitcoin, be it a hardware or software wallet. Bitcoin cannot be blocked, don't forget
As for
'cashless society' and
'cash might be able to exist in technologically evolved form': that's one of the beauties of Bitcoin. It's similar to cash. The keys that you have are not like a bank card that entitles you to a certain balance, which someone may modify or restrict your access to.
The keys are the money. Quite similar to holding a dollar bill in your hand instead of giving it to the bank and having an account balance in a database somewhere.
As long as you have your keys and a way to broadcast transactions, you can pay. If your country forbids / blocks Bitcoin traffic, you can use Tor. If they control Tor, you can use a VPN in another country. If all fails, you can send those transactions without internet - use ham radio!
Fears over government interference and internet surveillance have given rise to some novel experiments in sending offline transactions as somebody has transmitted bitcoin internationally by high frequency radio… through a snowstorm.