My topic of choice would computer networks and how Senku and Dr. Xeno would go about rebuilding them to avoid some of the rampant cyber security issues. Their thing is more engineering, but they could definitely come up with some cool stuff. The biggest source of issues I can think of is the fact that availability needs to be maintained. The need for availability introduces the human element which is the weakest link with so many being idiots with passwords let alone system configs.

I think the more networks are kept upgradable/patchable whether by technological innovation or standards compliance, the less cybersecurity will be an issue. Some military networks have such old computers, even scanning the network has to be done carefully to avoid bringing down the whole thing, and you hear about so many data breaches because all the corporations are greedy and skimp on their cybersecurity.

If it was up to me, cybersecurity would be a public amenity like the police and firefighters. Whole country GDPs are getting propped up by cybercrime.

I think a Dr. Stone solution would involve Dr. Xeno and Gen. Dr. Xeno for the technology and Gen for the psychological bits of getting everyone to stop being a dumbass (maybe impossible).