There are many problems for them with the current system.

So name me a single technical problem that will have more complex solution than building completely new system from scratch.

I'm focusing on technical aspect, not juridical, legislative or whatever, because only technical problems could not be solved by just signing some paper.

Cash/debit cards (to a lesser extent credit cards) makes that difficult and cumbersome etc.

How? Technically. It is just a databases, where you could add fields, triggers, procedures, views, functions and create any logic for user you want. It is well-established, carefully tested and ready-to-go things in every single implementation.

CBDC wont be allowed to be exchanged to cash like debit card/credit card is.

What stop elites to not allow cash withdrawal from accounts? They already easily do that during coronahoax and sheeple gladly accept that fearing scary virus on dirty sheets of paper. There is no problem for them at all in that.

It's not a representation of cash, it's a new currency entirely.

Card/bank account never was "representation of cash". It is cash always was representation of official currency. Card/bank account was another representation of official currency.

So why they need "new currency", if they do? I'm not shure that CBDC will be "new currency". Everywhere it is "digital dollar", "digital yuan", "digital rouble", "digital %your_currency_name%". Not something completely new like "amero" or like euro was.

There are many problems for them with the current system.

So name me a single technical problem that will have more complex solution than building completely new system from scratch.

I'm focusing on technical aspect, not juridical, legislative or whatever, because only technical problems could not be solved by just signing some paper.

Cash/debit cards (to a lesser extent credit cards) makes that difficult and cumbersome etc.

How? Technically. It is just a databases, where you could add fields, triggers, procedures, views, functions and create any logic for user you want. It is well-established, carefully tested and ready-to-go things in every single implementation.