Is it fair to expect people to reply quickly to messages at all times?

Personally, I feel it's not fair to expect instant replies all the time. The main reason is that people have different schedules and priorities, which can make immediate responses unrealistic. For example, in my work as a UI designer, I often receive messages from clients or colleagues, but I can't always reply right away because I might be in the middle of a project or focusing on a tight deadline. And that's largely because deep work requires uninterrupted focus. That said, I do think it's reasonable to expect a reply within a reasonable timeframe, say 24 hours, especially for work-related matters. It's about balancing responsiveness with the understanding that everyone has their own pace and responsibilities.