Also Macports works in a multi user environment without problems (as long as one either gives all users sudo access or sudo port access).

Does MacPorts have anything like Homebrew Cask? I know it's technically a plugin/addon, but it owes its existence to the Homebrew tooling and ecosystem it's on top of.

The ability to very easily install full GUI apps, or closed-source ones, is absolutely indispensable for automatically configuring Macs in many large environments, especially those (like a former one of mine) that heavily used Puppet for provisioning.

If MacPorts is lacking in that "umbrella package manager" functionality, I'd be stuck using both it and cask if I switched (and, given my positive experiences with Homebrew core and cask, I have no plans to).

The MacPorts system is flexible enough that you can use it to install any kind of software.

Honestly I don't know if that's popular, when using Homebrew and MacPorts I was always installing open source stuff...