Which is pretty much the case with Visa and MC too. There's little card payment fraud in Europe thanks to mandated strong authentication, and very low transaction fees as interchange is capped by the EU; card issuers don't initiate chargebacks so easily.
You're confusing fraud as in unauthorized payments with fraud as in you not receiving what you paid for. The latter is not prevented by 3DS in any way.
Ask anyone who tried to dispute a purchase that happened within the EEA, whether online with SCA or card present with PIN, card issuers often tell you to deal with the merchant directly. The interchange cap has significantly reduced revenue made on card payments, they have an incentive to avoid unnecessary manual work.
It is not. Wero has charge back support and therefor higher fees. There is quite some interest in Pay by Bank via PSD2 APIs. This is much more similar to iDeal and can work for the entire EU.
I've never used iDEAL but I assume the confusion comes from the fact checkout widgets (e.g. from Adyen) are transitioning from iDEAL to "iDEAL | Wero". I assume UX is the same, i.e. scan a QR code with your mobile wallet app?
If I understand correctly it's developed by the same people: Payconiq.