A new language is in part to discover a new place in the space of languages that isn't already well represented. OOP has been done since Smalltalk-80 and many of the class-based languages that followed. Deep class hierarchies worked well for developing widget trees and not much else. Now we're looking for a different trade-off since the constraints of hardware are different than before. Immutability performs well with multicore we have enough memory and advanced gc to not need to reuse mutable objects to conserve memory. Working in a mostly functional style with few key places of reference updates to large structures are much more clear and debuggable.
Many of the newer languages are multi-paradigm trying to find a sweet spot that either takes the best of each and add something new or tries to capture a large audience with features.
Many of the newer languages are multi-paradigm trying to find a sweet spot that either takes the best of each and add something new or tries to capture a large audience with features.