To be honest, the factors constraining the cross-world teleportation array, aside from the need for a large number of rare materials, mainly lie in the energy consumed each time it is activated.
After all, every activation consumes a large amount of immortal crystals, which power could afford that.
Even the wealthiest forces can't bear the burden of activating the cross-world teleportation array multiple times.
More importantly, if crossing into other worlds brought benefits, then these forces wouldn't mind the losses.
The issue is that even if one travels to another Great Thousand World, there's no guarantee of gaining much benefit.
The resources available in one's own Great Thousand World are already beyond measure, so why bother going to other Great Thousand Worlds.
Of course, if the cost of the cross-world teleportation array were to significantly decrease in the future, then travel across myriad worlds would naturally become popular.
