The chief problem is the ridiculous amount of carry on baggage that is now permitted / tolerated by most airlines versus the lack of locker space - and the penalties for putting bags in the hold that some carriers charge.
This ludicrous situation will continue until, heaven forbid, there is a serious accident, in which the evacuation is hindered by the sheer quantity and size / weight of bags that are in the cabin. Even several years ago I felt very uncomfortable flying with Swiss on an RJ when there were so many bags not just in the lockers, but packed around passengers in their seats, that if anything had happened I serious doubted if I could have escaped, should the worst have happened.
When the inevitable happens we'll see the regulators rushing to shut the proverbial stable door, after the horse has bolted, but it will take the needless loss of some lives to get a return to some sort of sanity.