Thank you for your valuable input!

Very true, informing unsuccessful candidates will give them closure on the application process and also elevate the company brand as an organization that cares about people. And yes, there are all sorts of hiring managers :) Although I've been lucky to have great managers throughout my career, I've seen the other types who are not adept at people skills.

One of the companies I worked for had a thorough process to analyze turnover. For employees leaving voluntarily, they had standardized exit interviews, analyzed the answers, and provided feedback to the business line, asking for an action plan and monitoring its execution. For terminations, they also investigated the reasons and did a pulse check on the department culture. For a number of years, this company was ranked one of the "Best mid-sized companies to work for." It's not an easy task but can be done with the support of top management.