Where does Swift fit into this? I haven’t followed along but believe it’s open source and a search appears to confirm this?

Swift language is open source but the entire ecosystem is as closed as they get. The fact that no one is building anything outside of the ecosystem says everything about Swift and Apple’s intent. The fact that they still won’t support Linux on M chips also says they don’t care.

Not never. Woz championed some of that in the 1970s. It's before my time, but the Apple II was pretty open as I understand it.