Why do women do this?

Sorry if this sounds like an accusatory Q, I’m just a little frustrated. I notice how a lot of women on here will respond to DM’s one minute, then stop the next minute. Nothing changed, they’re still online and posting, the message I sent is no less interesting than the previous. So what changed?

I know women get a lot of messages but why not either respond to each message (from one given person) every time, or just not respond not at all? Instead of sporadically switching between responding and not responding?