InDesign has been dancing around the edges of this idea for years, with half-baked features like snippets, libraries, linked items in the content grabber....but it never has gotten it right. What we need is something exactly like the "components" feature in Adobe XD. We grab some objects, and then "Make Component" out of them. Then we can plop multiple instances of that component throughout the document. If we go back and edit the "Main Component" those changes are automatically applied to all placed instances of it.

Yes, I know you can place one indesign doc into another, which is the workaround I've been doing for years. But that is very slow and clunky in practice. One reason is we're handcuffed to the "page" and "page size" mentality. Many components—being just collections of shapes/objects—do not need a set "page size" and it's annoying to have to keep adjusting a page to fit the objects as they evolve. Another reason is file management. If we put all our "components" into separate indesign files, it becomes a pain to share styles/swatches between them. If we group them all in one indesign file, we're then limited to referring to them only by page number (since we STILL can't name our pages). This gets cumbersome as we add/move/removee pages and place the items "by page" into our main indesign document.

Snippets, content grabber, libraries, do not create "linked instances of editable main components" in the same useful way that XD does.