It depends. Are you very close with these people?

There might be many reasons for not replying. Most people don’t text at work so after work they only have a few hours to take care of their household and children and heck they might be exhausted. If in addition they have 20 texts to reply, they’ll prioritize. If it’s not an emergency, they might forget to reply or run out of time. It also depends what you send. Is it something urgent? Essential? Most people are very busy

Hypothetically speaking not replying to texts is not polite. But you have to be realistic. For example… If you have an infant and a toddler and an elderly father to take care of, there’s no time for random texts.