I want the judge to keep the lawyers in check so they cannot. Judges are trustable because the jury limits their power. If I am a lawyer I know whothe judges are and it is to my advantage to figure out their bias (including judge shopping if there is more than one in the area), looking for embaressing things or blackmail material, what bribes they will accept (often in form of donation to a family charity) and so one.

which is to say the reason I trust judges is the jury keeps them in check by ensuring there isn't value in the above corruption.