After 19 years taking care of bees and sticking my hands in ovens, I'm telling you that brake pad wear is pretty much like how a good baking tray wears down: it depends on how much you use it and how you treat it. In your case with the 2019 Ibiza driving around the city, it's totally normal that they're worn out already. City driving is brutal on brake pads because you're braking every couple of meters, it's not like highway driving where you brake once in a while. 40,000 to 70,000 kilometers is the range you see floating around, but it can vary quite a bit. If you've had the car since 2019 and you drive a lot in the city, you've probably blown past those numbers without any issues. It's not that you drove badly, it's just how it works.
What other people don't mention much is that you shouldn't wait until they're completely worn down. When brake pads are really worn, they start damaging the rotor, and that's when things get expensive. The shop is warning you in time, so change the pads without hesitation. While you're there, take the chance to check that the rotors aren't completely shot. Sometimes mechanics give you a heads up about that when you see the final quote and it freaks you out, but it's better to invest now than pay a fortune later because you neglected maintenance. Take it easy the first few kilometers after the change, the new pads need a break-in period.