I’m not a carpenter by training, but I have built a lot of simple furniture, and blogged about a lot of simple furniture, and one of the rules of thumb I’ve picked up from the pros is that threading screws into end grain is a big no-no. Wood is not an isotropic material, because of the grain, and is relatively weak in that direction. But sometimes putting screw in end-grain is the best/simplest way to do things, and until I saw this simple trick from, the only way I knew to do it was to use a barrel nut or some other relatively unusual and expensive fastener designed for the purpose.