VR - It has been through a few hype cycles, but never quite makes it. Cost, weight, battery life (or tethers), lack of highly desirable games, required floor space, nausea (in some people), etc.
Starlink - when announced it sounded like the solution to ISP monopolies and rural broadband access. But the roll out was so slow that other solutions have caught up. For people with no option other than satellite internet, it is still great (if they can get it) but for a lot of people, better options now exist.