Why Does HR Suck?

So I've been actively looking for new opportunities within the data science field over the past couple of months in the UK and Europe and I have to say I am completely dumbfounded by how terrible talent acquisition teams/HR in general are at facilitating processes. Now I get that most large corporations get a ton of applications for most positions they advertise (and especially in the field considering all the hype) but do these people not care about at least doing a good job post their initial CV decline? An example of what I'm talking about is setting up an interview, then just cancelling on the day with no reason given. Or setting up an interview and not pitching or being extremely late. Or saying they'd like to do an introductory call and then not following up. The process is daunting enough as it is, do people just not care? I thought HR is about working with people, so you at least have to have some level of empathy.