The tier system in 3.5 was pretty accurate. But that was a throroughly flawed, weared out system.

And that system had a pattern to it. It was Prepared Casters>Spontaneous Casters>Limited List Casters and ToB Classes>Classes that can be really good at something>Classes who can be kind of good in something>Classes who can't even be good

The point of that tier list is that if, at the same table, you have someone playing a Tier 1 class and another a Tier 4, you run the risk of the former player overshadowing the latter completely.

In 5.0, we don't have such objective layers. In one of my earliest games, the most reliable single target damage dealer was our longbow ranger, that class that is considered the "weakest" by many.