There are more secure alternatives. Are you sure those you listed actually use it on the servers? I would guess that at least Spotify and Netflix uses some other container runtime than Docker on their production servers.

For a long time Docker was helpful and opened exposed ports on the firewall. So you wanted to access your redis ports locally and exposed it on the container? Now everything in there is accessible on the open internet.

I believe they've fixed it but I haven't used Docker in years so I wouldn't know.