Wero does several things. You can already send instant payments if you fill out IBAN and such, but entering order numbers, account references, and other such cruft for purchasing products is a pain. Companies receiving such payments also need to connect payment to a user and update their digital processes somehow. Wero offers such a solution so you don't have to find a PSD2 processor (which will probably cost just as much).
For interpersonal transactions I don't really see the advantage here, but for commercial use cases it's got a solid product and purpose.
Wero doesn't stand to benefit much from payment fees as European payment fees are already rather slim compared to, for instance, American ones (crazy things like percentages of purchase price with a minimum amount!).
So how can a QR code not supply the necessary data? Example:
payment://iban=XXXXXXXXXXXXXXX&amount=12.34EUR
Any bank app should be able to read this. What is so complicated? Right, nothing. Credit card companies are a hidden tax, worse, they are a tax on turnover, not profits.
But in EU you don't usually get credit... The cards are often debit only. Yes, credit cards do exist but they are not like the american cards, and things like chargebacks are not super simple. I for example haven't had a credit card over a decade now...
Chargebacks exists for (EU style) debit cards, too. It doesn't need to be simple just available, so if the merchant disappears with your money or someone uses your stolen card, there is a way you can get your money back. With bank transfers that's not possible (at least here).
For interpersonal transactions I don't really see the advantage here, but for commercial use cases it's got a solid product and purpose.
Wero doesn't stand to benefit much from payment fees as European payment fees are already rather slim compared to, for instance, American ones (crazy things like percentages of purchase price with a minimum amount!).