How similar are Ibiza and Fabia?

Good morning community My father is playing with the thought of getting a new Fabia. To my objection he should get then an Ibiza, because that would be anyway the same car only in my opinion better design he said that he had talked with someone from the workshop and the Ibiza should probably still be qualitatively worse. Well I always assumed, as noted, that the two cars are technically practically the same only the cover and If someone else can tell me something about the cars I would also be very grateful Happy Easter Christoph P.S. I post it here and also in the Skoda Forum, because I don’t know where it is better kept