That's to easy. There is a miriad of problems how the hiring process works:
Getting sued by applicants because they feel discriminated by something one way or another.
The cost of hiring and training new people. Yes, it's a catch 22. Companies look to minimize the risk believing the longer and more interviews their hiring process includes the likelier they are to hire the perfect fit for the role. Many people I interview with on my end have no clue what to ask, at best they ask questions I hardly understand or that have nothing to do with the actual job. Then their feedback includes highlights like they felt they looked funny and that was something off. Great job, buddy... Then you provide them with training - which they should have received BEFORE being allowed to interview people. Of course the trainer was shit and didn't have a clue. Which to be fair, a lot of times this is actually true because someone told some HR lady she'd make an excellent coach and she actually believed it :(
People no longer see things through to the end. Meaning especially younger applicants have been taught that companies have to cater to their feelings and that everyone is a winner and deserves a promotion after a couple of months on the job.
Glassdoor. Yes, this is an issue because companies care more about how they are being perceived as opposed to who they really are and more importantly how to genuinely better themselves. It's all smoke and mirrors and it works. Until people find out they joined a cesspool of toxicity and compliance and leave resulting in a never ending stream of inexperienced people.
Not training employees properly and giving them time to learn the ins and outs of the role and to connect with other employees and departments. It means they aren't given a fighting chance from day 1. Which spirals out of control pretty fast.
Not utilizing people who have been doing the job for decades. This one baffles my mind. Yes, some of the old timers don't sing the company line at every occasion, they just do their job and they have been doing it for a long time. They may be more difficult to deal with but it's because they have seen it all come and go. Every "new" review process, training, team building, procedural change... You can bet your ass they've seen it time and again.
HR. They actually face a problem that they don't produce anything. They are a cost center and the way they justify their existence is to try and constantly reinvent the wheel by trying to implement something they've seen on Linkedin. Doesn't mean they understood it but it sounds cool. So they do what other departments in the same situation do and come up with old bullshit. The problem is that if Tammy in finance does this only her team suffers. But HR see the big picture and make everyone suffer.
The boss man's expectations. The smaller the company the wilder the changes in strategy and direction because a lot of MDs, executives,... think due to their title they must know best. So whatever brainfart they have is a godsend and must be implemented at a moments notice.
"Difficult people", usually employees who wanted to contribute and improve things whose spirit and motivation has been whittled away by nay sayers and convoluted processes. They once had to say something and now have been labeled as toxic because their company sucked the life out of them and they gave up.
These aren't the only problems and their significance varies a lot. What I want to say is that appearances and playing politics have become the most important factors in companies.