Character Optimisation is Pointless (Unless You enjoy It)

I understand the urge to make your character as good as possible. But, to a certain extent, min/maxing your character is pointless.

A typical character optimisation cycle goes something like this:

1. A player optimises their character to be particularly good at something. This could be their physical attacks (melee or ranged), defences (typically armour class), spell casting power or a particular skill. For their level, this character is epic. They rule.
2. The character begins adventuring and crushes or defeats everything standing before them.
3. The GM notices this. The GM wants to challenge the players and includes harder monsters, opponents or challenges in their adventures. The GM isn’t (hopefully) trying to kill the characters, just challenge them.
4. The player (or players) notice the adventures are getting harder and tweak or optimise their characters to be even better at the thing or things they are already awesome at.
5. The GM notices this. The GM wants to challenge the players and adds in even harder monsters, opponents or challenges in their adventures. The GM isn’t (hopefully) trying to kill the characters, just challenge them.

Repeat steps 4-5 until someone gives up.