I can pretty much tell you definitively that every barrister who practices law in a London-based chambers has been to OxBridge. Starmer (he of the B,B,C at A-level) dipped himself at Oxford as a postgraduate, so he was in the door.

After that point ..

Have you ever been in a team where, whatever you do right, the correct person gets the credit/blame :-)? As a mediocrity, Starmer’s route to career progress was via precisely the characteristics you describe (roughly summarizable as a “safe pair of hands”), combined with credit for the successes of others, or failures that could be blamed on others. It always works, which is something people with integrity usually realize after its too late.

- Best regards, Shyaku