In King Lear, the Fool is a satiric voice of reason and wisdom: comparable to a chorus in Greek plays. In Act 1, Scene 1, Lear gets selfish flattery from Goneril and Regan and he falls for their effusive compliments thinking it is love, when in fact they are just patronizing him, knowing what they might inherit. Cordelia is above such disingenuous groveling, but Lear takes this as a sign of disrespect. Lear promptly banishes her with no dowry, sending her to France.
The Fool recognizes that Goneril and Regan were thinking only of themselves and knows that Cordelia was the only sincere one of the three. In fact, the Fool is heartbroken since Cordelia has gone. The Knight tells Lear, "Since my young lady's going into France, sir, the fool hath much pined away" (I.iv.62-63).
The Fool cared for Cordelia but he also knows the absurdity that Lear banished her, his one honest and loyal daughter. The Fool tells Lear he had this coming because Lear gave all his power to Goneril and Regan. Lear "deserves" it because he fell for their flattery rather than recognizing Cordelia's honesty. Telling Lear that he put himself in this powerless position, the Fool says:
I had rather be any kind o' thing than a fool; and yet I would not be thee, nuncle. Thou hast pared thy wit o' both sides and left nothing i'th' middle. (I.iv.151-53)
In other words, Lear gave his kingdom to Goneril and Regan. The Fool knows they will wield this new power over their father, and Goneril takes his attendants away and orders Oswald to be disrespectful to him. He is now beholden to his two disloyal daughters.