Someone will probably shoot me down for this but I actually find ChatGPT good for explaining concepts to me. Especially when I just want a high level understanding of a concept as I try to understand another one without getting too bogged down. A lot of Google results go into way too much detail.
There’s various contractual reasons they may say this but ultimately they probably can’t tell. Those terms and conditions don’t count for anything and can’t be enforced because no reasonable reads them. I’d just go ahead with using your router and wait for somebody to say something (feign ignorance).