Crop sensors aren't likely to go anywhere anytime soon, as they are simply too cost effective to produce. Due to die layouts for production you can get something like 5 times as many crop sensors as full frame. A flaw that renders a full frame sensor useless can then mean rendering 1/5th as many crops useless. Numbers are possibly even better, depending on design and die layout.
They are also useful. If you're going for telephoto and high speed shots where you are likely going to crop out much of the image anyway, then why not start with a crop sensor? As long as people are shooting wildlife then you are going to have demand for high quality crop sensors.
Originally Posted by Lrrpie-CT
I destroy drives for clients all the time. Sometimes, intentionally.