The Dutch do nothing but use Ideal, Wero's predecessor, for online purchases. People very much want to simply transfer money from their bank to a shop, just as they can with a debit card. Most Wero transfers will be to shops in your own country, but don't underestimate its potential. Valve offers Ideal on Steam, and has done so for years now, and they can probably give some very appealing insights into how that unlocked a massive amount of gamers in the Netherlands.
Nobody is worried that Valve isn't going to deliver what you purchase on Steam. Likewise few people are worried that they're going to be scammed by a well recognized national brand. That's why I specifically mentioned cross-country online shopping, where methods like Wero which offer no benefit at all to customers will have difficulties finding success. Unless there's a massive media campaign to tell people what they should do.