HR-Manager just there to see your entry and exit!

What is HR-Manager expected to do in a company? I hate to hear that HR manager is just another manager. No doubt, he is a manager but what is he supposed to manage? At least in big tech companies, sadly role of HR is very limited. For good or bad, HR isn't anyway different from any other manager at least in bigger organizations.
When someone entering, their role is limited to make sure that the human resource is through filling up all the formal documents. They are not involved in the entire process of recruitment at all, sadly. It reminds me of the executive selling credit cards. Sir, "you just have to give a copy of your pay slip and ID card and leave the rest to me". Applicant imagining the ultimate deliverable (credit card/job), signs at few places without knowing what he is accepting upon. Much similar case here too.
When it comes to someone exiting, the role of HR is limited to explain the details of the benefits, printing out the relieving letter and so on. HR should ideally be conducting the exit interview for the much needed feedback to put things in place. Of course, this is not enough if they limit themselves for just entry and exit but they are required to act during the entire journey.
Desperate to make their presence felt, in every employee meet, they appear well enough so that they get recognized. I guess, it has to go beyond that. How many of us think of HR when someone tells us that his work environment is utterly bad? When it comes to improvisation, no one believes the role of HR. None seems to have a belief that HRM has the abilities to bring in much required changes to make the company a better place to work. If they themselves do not believe in their abilities to change, who else will?