A global undersea cable network has been in place for 30 years. It's woefully overcapacity 24/7.

https://www.iscpc.org/information/global-submarine-cable-systems/

It takes huge capital and time to lay cable, and the point of doing it is that you're booking bandwidth from ISPs, often years in advance. There's competition, but it's also a seller's market because of huuuuuuuge bandwidth demands.