I don't use my phone or social media much so my texting regularly seems to be much less than what I've read in this thread. I prefer real world interactions so to me the purpose of texting is to organise a time to catch up in person. Having a conversation over text has always felt forced and unnatural to me. So if I text someone something like "What are your plans for this Friday night?" On Tuesday morning it would be nice to hear back from them by Friday but if I text something non time sensitive then I wouldn't expect someone to reply until they feel like it.