Judges that aren't on specialized tribunals aren't expected to, and mostly don't, know the law (because it's quite impossible) - they rely on the Barristers to inform them, then get their clerks to do some digging to see if the briefs are on point. The higher up you go in the chain, the more clerk time they have to research and the more control they have over how long they take to put out their ruling.
Junior judges are more reticent to rock the boat - they have less resources, less understanding of how the judicial boards and other oversight mechanisms work, etc. Old greybeards generally stop caring - either about bothering to change things or about how 'safe' their ruling will be on appeal. The most active in tossing bad precedent out the window generally end up being the ones that get appointed to higher ranking courts.
Junior judges are more reticent to rock the boat - they have less resources, less understanding of how the judicial boards and other oversight mechanisms work, etc. Old greybeards generally stop caring - either about bothering to change things or about how 'safe' their ruling will be on appeal. The most active in tossing bad precedent out the window generally end up being the ones that get appointed to higher ranking courts.