As I have pointed out several times now, groups in which the clerics and wizards primarily buff themselves are playing sub-optimally. And yet "experienced" players keep holding it forth as an example where game-balance breaks down.
And there is an observation to be made there - optimal play is perhaps not only defined in therms of "what gets my character the highest effectiveness by some measure of numbers".
What, overall, is/are the goal(s) of the game? Optimal play should be considered with respect to the goals.