Allright, let me try and end this argument here.
Take a look at Feat: Expanded Knowledge - Learn extra power of one level lower than your current maximum.
Take a look at Erudite class feature: Convert Spell to Power, understand that all arcane spells are now available as powers.
Take a look at Geomancer class feature: Spell versatility, understand that all divine spells are now available as arcane spells.
Understand that with Expanded Knowledge, Psychic Warriors have access to any and all spells and powers below level 5th in some classes spell list in the whole game.
What this means? Access to Invisibility from Telflammar Shadowlord as level 1 spell, Improved as second, Haste as level 1 power from Trapsmith, etc. Divine Power, even. Now, with Invisibility the PsyWar can buff himself for practically unlimited time. Improved Invisibility from level 7 onwards means that fighter will have to invest in way to see invisible or get autoscrewed, etc.
Now that we know that PsyWars can manifest Divine Power and well, just about anything, I leave it for your imaginations to prove that figher can't compete.