Single.

Why are women so into taking it slow these days?

Let's take some time to analyse this. Taking it slow would mean that you'd have to actually take time out to get to know her. Nothing wrong with that. BUT, the fact that you do gives away one important clue. It tells her that you're interested. Many will agree when i say that once a woman feels you're interested in her, the whole scenario changes. She'll be unavailable more often. It'll take longer for her to reply to your messages.

Which leads me to my second question: Why do they do this?

Do they do this out of spite for men that like them? Unlikely. Is this their way of saying that they're not interested? Possible. I'm out of ideas here.

Getting to know someone isn't as easy as it used to be.