Well, It’s Sort Of True Only The Strong Will Survive
The only way it won’t is if its species has a society of some type where the blind or terrible-seeing person, plant, or animal can rely upon aid from others. This will take a community or society of some type. It can be quite helpful, therefore, to be in a species that will have a pack mentality.
In fact, out of all animals that have ever been on Planet Earth, the least likely to go extinct are those that use a “pack mentality.” Essentially, the “only the strong survive” concept is sensible but only so much. It is true in terms of the species that go it alone mostly, whereas it’s not as big of a problem in species that naturally travel in groups.