Best/worst. I worked at an e-learning company that, thanks to ancient e-learning standards,
really tried hard to figure out when a user is leaving a web-page to handle session exits gracefully.
sendBeacon was dead on arrival, for that purpose at least; iirc it's blocked by most ad blockers. (Or was, who knows with Manifest v3.)
Similarly we're unlikely to see sendBeacon truly replace tracking redirects, unfortunately. This isn't an area where tech firms are happy to see fine user controls.
