Your dislike is unfortunately a common flaw with Casper like foam mattresses which largely just have a number of layers of foam on top of one another. You can r

Your dislike is unfortunately a common flaw with Casper like foam mattresses which largely just have a number of layers of foam on top of one another. You can reinforce or line the edges with firmer foam/material so that sitting on the edge is more comfortable and robust, but I think a lot of mass manufacturers avoid that to keep their costs low. I recall seeing the difference by going to a custom foam mattress store.