Why people take so long to text back?

Just wondering like I had been texting a guy from tinder then we moved to snap and all of a sudden he leaves like 30 mins before opening the snap and before it was quick responding. I don't really mind just curious why people do that?? Even my female friend takes like an hour to open peoples snaps shes interested in I'm like ??????? I open shit so fast like lemme talk to youuuu😂😂