Vagrant is for development environments. Terraform is for more general infrastructure management.

Vagrant provides a number of higher level features that Terraform doesn't. Synced folders, automatic networking, HTTP tunneling, and more are features provided by Vagrant to ease development environment usage. Because Terraform is focused on infrastructure management and not development environments, these features are out of scope for that project.
https://www.vagrantup.com/intro/vs/terraform.html