A great example of bullshit megaprojects that governments announce with no real intention of ever implementing. I searched and tried to find something recent about this project. Pretty much everything I found was around the announcement in Nov 2021 - the latest article I found was this one from Jan 2022, https://dialogue.earth/en/energy/50155-chile-underwater-cabl... , which states the project "does not yet have feasibility studies or a form of financing".
China could absolutely do this if they want to, but they may well have better things to do with all the aluminium their rapidly expanding factories are producing.
At this scale it's not even mainly financial, it's opportunity cost and geopolitical considerations, on both the pro- and con- side.
I also would like a magic pony.