It is really interesting to consider what our computing environment might look like now if some of those “dead ends” had been developed further.
There was at least one other computing system that took up the cause of vector graphics in the early 80s. A Canadian project called Telidon tried to establish consumer grade videotex networks using a vector encoding that could render relatively sophisticated graphics given the limited computing technologies of the day. That encoding eventually became a North American standard, NAPLPS, after AT&T got involved.
Videotex never really took off in North America, but NAPLPS outlived Telidon into the BBS era and beyond. The same optimizations that made it useful for videotex also made it well suited for transmission over phone lines at 1200 baud. In its most widespread deployment NAPLPS eventually became the basis for the Prodigy Online GUI.
While NAPLPS was well optimized for limited storage and bandwidth the same could not be said for processing power. Relatively expensive, special purpose hardware was required to render NAPLPS in the early days, and that as much as anything accounted for Telidon’s failure to get much beyond the field trial stage.
It’s possible to imagine an alternate reality where the cost of processing power declined throughout the 80s and 90s, but the cost of bandwidth and storage didn’t. In that reality I think NAPLPS and other vector graphics systems would have been adopted far more widely than they were.