the exact opposite - it is easily the most valuable thing I get from any credit card.

The comparison with that QR fare is a bit misleading: the overwhelming majority of long-haul J return flights will cost more than double that.

You need to be flexible to use avios, that's all. Unless you want to go to New York or plan 355 days in advance it is unlikely that you will be able to use it to get you a flight on the exact dates you want to the exact location you want, and for many locations you will be lucky to get any availability at all. However if you plan well ahead or just want to go somewhere and are prepared to take the best of what is on offer it can work nicely.

In your case I would take the QR fare from Pisa (it's a far better product and you will have far better choice of dates and times); and save the companion voucher for your next trip.