When I was a student, in 2001, Poland, I had such functionality - I had separate sub-accounts, each one of them with a dedicated IBAN number, receiving funds.
My monthly allowance from the parents went to one account, my payments from clients (freelance programming) went to another one. From that I distributed the money into another account for holiday savings, and to a spending account with a dedicated and free wire transfer of $5/day for daily spending - the only one I attached a debit card to.
Once I got a browser in my phone, I think around 2004, in case of emergency (as in "standing in line at the store, and discovered I'm $2 short"), I could transfer the money between various accounts instantly.
Another cool thing was that since my father had an account in the same bank, I received all the wire transfers from him instantly. As in, I call him, ask him for extra $100 for something, he says "hold on", opens up bank account on his browser, sends the money, and I instantly get a text message that the funds are received, and I can politely say "thanks dad, I got it" before disconnecting :)
Using past tense, because that was all in 2001-2004. 16-18 years ago. Right now I think all the major banks offer that, so nobody considers it a big deal any more. Oh, and now we have instant inter-bank transfers, but they cost "a lot" - like a flat fee €1, so people usually send the regular free ones, which take <1 work day to get delivered (<3h if you send them between 7am and 5pm) - regardless of which bank you are using.
I use a python script to download most transactions from banks/credit cards. https://sites.google.com/site/pocketsense/home/msmoneyfixp1/...
There are enough people who do this that you can figure out how to access the OFX endpoint for most financial institutions.
One problem I have with relying on OFX is that I have a nagging suspicion that it's not as 'official' as the statements. If there were a discrepancy between the two, I'd worry that I wouldn't be able to resolve it in my favor without having reviewed (and thus downloaded and reconciled against) the statements.
I really think the state of how bad consumer bank integration tech is has led to this reality of login and scrape that you have with yodlee & co.
Otherwise, it requires only an email (and that you pay them 5$/monthly somehow. Paypal, credit card, whatever).
If you don't want auto-import (which doesn't even work for my credit union anyway), you can uploads .csvs, or manually input your transactions.
LWN have a current "Grumpy Editor" series article on Beancount:
https://lwn.net/Articles/751874/
And an older one from 2009:
Heck not even real "Accounts" (in the traditional banking sense) but just "funds" or "virtual accounts." I should be able to put $5/month into a "waste of money" fund, and then flag specific transactions against that balance when I use it, or as you said have a virtual credit card that goes straight out of my virtual "waste of money" fund.
It really is surprising how little innovation occurs in the banking space. I want more tools to track expenditures and money usage, silo-ing money virtually is an obvious way to do that, but yet nobody really offers it!