Contactless requires the acceptor to have a specific piece of hardware that comes with a contract.
The QR code is an image, that AFIAK contains instructions on a specific transfer (target account number, amount, reference etc) in a machine-readable format, that the sender can chose to scan and accept or not.
Neither is "better", they have different uses.
My take-away from this tedious thread is that Wero does not currently support contactless. It is fine to admit it (I don't why people turn into fanboys over randopm things) but that does make it of limited use for in-person transactions apart from niche use-cases and, certainly, this means NOT "Goodbye to Visa and Mastercard" just yet.
Although contactless through banking app go through Google Wallet these days, which I hate, so I would prefer if there was a European alternative for that. Could be part of Wero, but it doesn't have to be. As long as it's not part of Google.