Texted others 100 many times, but didn't reply once or twice. Is this normal?

Normal. The other party has no time or forgot to reply, or may be busy with other things and can't reply in time. Everyone has their own habits and preferences in communication. Just because the other party doesn't reply to the text message in time doesn't necessarily mean that the other party doesn't value you or has other problems. Understanding and respecting each other's thoughts and feelings is an important prerequisite for maintaining good interpersonal relationships.