If you choose to respond, and really why would you it's absolutely none of their business, all you need to say is what you said right here - rent went up by 35%, Company X raised pay by 1%. And phrase it that way, that "Company X increased pay by 1%". Make it about their actions, not "my pay only increased by 1%" or "you only gave me a 1% raise." DO NOT put the focus on YOU. Make it about the company and . Maybe throw in that even after making record profit, Company X only gave 1% raises. The people running the company need to know that their choices and actions have consequences and this might be one of them.
But really, it is none of their business and there is no reason yoou should answer them. Maybe you met someone and are moving to be with them. Maybe you inherited propedty and are moving there Maybe you hate whatever city it is and are just getting away. You WFH, it doesn't matter and it's none of their fucking business. As long as you are doing your job, they don't need to know anything about your life.