You can just go on forums like crimemarket.cn and find hundreds of people using fake IDs to open bank accounts in Germany. It's really not unusual at all in Europe.
Banks don't do much to verify IDs, they almost never even check basic security features like OVI and OVD. Usually they don't even bother with UV.
Anyone can print flawless Romanian ID cards with an inkjet printer and some teslin sheets at home, those are valid everywhere in Europe and you can even safely fly with them (outside of Romania, obviously) if you feel so inclined.
The printing inside the country is so inconsistent that they're literally impossible to authenticate offline https://temp.sh/oZGbx/ROMANIAID.pdf
Have you seen what Greek ID cards look like?
Every day, thousands of bank accounts are opened around Europe with fake IDs.
> Also it's risky to use, as forging IDs is a felony by itself, and you'd risk immediate arrest by going to a bank and trying to use it
Except not really because you'd just make sure that the ID is good before you go to the bank. Just compare against a real one or check on PRADO.