@iona HK is worth visiting for several reasons. #1 is food, #2 is just walking around in the world's overwhelmingly scyscraper-densest place and going up in some of them for the view, and then there are some stark contrasts between the ancient and the hypermodern to enjoy.
For the cyberpunk experience, you can get some of it by just going to obscure warehouses and meet small businesses, and you can get some of it by going to the electronic markets in Sham Shui Po. But the real deal is Shenzhen. They have like 200+ makerspaces and markets where you can buy every component imaginable.
While staying in Hong Kong, one can make visa-less day trips to Shenzhen.