Think of facebook like an organism subject to evolutionary pressures. The evolutionary pressures that matter to facebook are maintaining "engagement" and throug

Think of facebook like an organism subject to evolutionary pressures. The evolutionary pressures that matter to facebook are maintaining "engagement" and through that ad revenue. Note that what matters to FB isn't engagement between you and your friends, just between you and it. So it doesn't matter to them how poor the algorithm is. The only thing that matters is how many minutes or hours a day you spend on the site.