Is there a name for this new-age method of notes/webpage/data productivity genre? They all seem to have "write with /" to insert "block" content.

I am trying wrap my head around what they are. The seem to be "docs" on the web. Then they also have this "inline page" feature which is a fancy include. Then have a table insert with a relation feature. Then they have a dynamic view layout engine on a table.

The term I'm familiar with is "outliners", as is used by Logseq: https://docs.logseq.com/#/page/start%20here

Unfortunately, this is quite difficult to search for, but it might give you some leads.

Block-based editors maybe?