I use Traefik because it solved a problem with the static configuration approach which Nginx had / still has.

In a scenario with multiple services behind Nginx, taking one down or replacing an instance is massive headache. I tried to script around it, but basically the Nginx container would choke on the fact that a service does not [yet / anymore] exist, and together with the docker networking stack it turned out to be an insurmountable problem.

Traefik otoh discovers services based on (in my case) labels on the docker containers running locally. And then updates the configuration on the fly. Basically this resulted in massive headache when I needed to enable zero downtime deployments and updates behind Nginx. And traefik handled it perfectly without dropping a single request.

Nowadays I manage my dynamic configuration with ansible and update the values in for the file-based configuration provider with a playbook. I don’t need a UI to manage my inventory, I use ansible for that. Traefik handles the rest perfectly.