If you get to choose your infrastructure that may be fine. If you don't and you work in even a medium size company you likely work with what they have, which is increasingly kubernetes.
That said, they still do not do similar things. OTP does not take care of orchestration if you must run more than 1 node.
You are still benefiting from OTP's supervision and scheduling when using docker or k8s, the difference is in what other features and the size you need.
No one is saying always deploy to k8s, but they are not overlapping.
Nor does using BEAM make it uniquely fitted to running on physical machines compared to other languages like java, go, C++, Rust, ... If your application is suited to running on a few droplets the language you are using is not likely the deciding factor for that.
That said, they still do not do similar things. OTP does not take care of orchestration if you must run more than 1 node.
You are still benefiting from OTP's supervision and scheduling when using docker or k8s, the difference is in what other features and the size you need.
No one is saying always deploy to k8s, but they are not overlapping.
Nor does using BEAM make it uniquely fitted to running on physical machines compared to other languages like java, go, C++, Rust, ... If your application is suited to running on a few droplets the language you are using is not likely the deciding factor for that.