Pointing out that Arya has suffered and adapted and survived does not undermine what Sansa went through. Acknowledging Arya’s struggles, intelligence, strength, adaptability, and perseverance does not discount Sansa’s struggles, intelligence, strength, adaptability, and perseverance. Stop interpreting positive statements about Arya as negative statements about Sansa.
There is no reason Arya wouldn’t have survived if she had been in her sister’s place. And that statement doesn’t detract from Sansa or her experience. It only speaks to Arya as a character and what she can endure and how she has already proven she can adapt.