Maybe "Why did you want to switch?" or "What do you think we can offer you that our competitor didn't?" or even "Is this position something you plan on staying

Maybe "Why did you want to switch?" or "What do you think we can offer you that our competitor didn't?" or even "Is this position something you plan on staying a while at, or will you jump ship to the next best offer as soon as it arrives?". Not "Hey, by the way, what are your current company's trade secrets?"