In a way Wave had been that enabling technology by becoming a compelling demo of Operational Transformation that was later incorporated into many other products with much more focused workflows (e.g. Google Docs).
OT is always "just fixing this one corner case" away from working. I can't blame Google they dropped Wave, extending, maintaining and fixing OT for new kinds of data/operations is a nightmare I wouldn't wish to my greatest enemy.
this is absolutely the case. first product that really demonstrated what plausibly-real-time sync / collaborative editing on documents could feel like (and this is back when AJAX was still (kinda) fancy)