The /people page looks a lot like albums based on face to me, is that not what you are talking about?

It seems like he’s saying that he could create an album and add a rule saying “add all pictures of John and Jan”

Not who you're replying to, but no - this isn't the same. You can't share that album with others. Or have others collaborate on it.

You can do this with a few scripts and the Immich API - but that's not something the average user will do.