Anything that doesn't have an external connector or some way to mount one. One example would be if you were using a USB Wi-Fi radio and wanted to connect it to the internal USB connectors but you'd need to pass the antenna to the outside of the case.

Not just for water cooling. It's for cables that pass in or out too.

This is the result of Microsoft being so cozy with hardware vendors.

You're the one that made the claim that they're the "only mainstream brand that cares about Linux". It's up to you to prove it.

You sure about that?. Where does this myth come from that Lenovo cares about Linux users?

should I develop for Amarok or Fooyin?

Fooyin would be my bet. The development is much much more active than Amarok and is a ground up new program, not a codebase from decades ago.

And now there's a foobar2000 on Linux

Better to just buy a System 76 or Framework.

Strawberry, qBittorrent, neovim

Cantata

Sadly it looks like it's no longer maintained

https://github.com/CDrummond/cantata