using models in frontend? (vue vs ember)

In Laravel I am used to define my models up front and to perform all actions on them.

However, it seems that most frontend frameworks just use whatever an API reponse provides and store the json data into simple arrays.

The only framework that I found using the model approach is Ember. I am missing this structure in the vue docs. I wonder why nobody seems to care about models. Are they just not that important in the frontend world?