HR is aware of employees that treat others terribly and do not take any action, especially with upper level execs. Some managers do nothing while watching their teams struggle to stay above water, then lie and throw others under the bus for their failures.
Management will continue to make empty promises regarding career development until you eventually just give up and quit. If you make complaints, you're told you should be happy that you have a job. There is no accountability and you will constantly have to hold managers accountable as a normal associate making pennies an hour.