VMware FT is enabled per VM basis while VMware is enabled per cluster
In the case of ESX host failure, virtual machines are the failed host and are re-started and powered-on the other active hosts in HA cluster. But FT-enabled virtual machines; there is no downtime. In the case of a host failure, the secondary VM will be activated, and it becomes primary and continue to run from the exact point where the primary VM is failed or left off.
