I think it’s a fairly common to exclude “which + to be” in “which + to be+ adjective” when using a predicative adjective.
It could as well have been:.
“..a world that/which is intent…”
“that” and “which” are so common that at times they become rather cumbersome and are just dropped out.
Another would be
The car which I saw in the garage belongs to Tom
Removing which:
The car I saw ....
(Here which is the object of the verb “saw”.)
Or still:
I live in Tambaram which is a town which is very close to the Coromandal coast.
If you had noticed the “which is” would have grown rather annoying.
So,
I live in Tambaram a town very close to the Coromandal coast.
But safer it is to stick to rigid grammar and use “which+ to be + adjective” instead of dropping them out.
And by the way, “intent” functions as an adjective although it is never used attributively.
Example: He is intent on pleasing his dad.<=> He is keen on pleasing his dad