Why are government officials avoiding questions about when life will return to normal?

Because no one has any of knowing for sure when.

Because it never will.  Please define normal.  I have no idea.

Would you prefer they lie and just do what Trump did on a daily hourly moment to moment basis?

No one wants to be the first to tell you life is never returning to "normal". Some countries may go back to something resembling the before times but in the US the pandemic has released numerous social and economic forces that seem compelled to upend the entire system. The only question is whether we'll destroy ourselves before our enemies do it for us. 

Because it's impossible to set a date right now.  Any number of things could happen from people refusing to get vaccinated to another major outbreak happening.  Setting a date is dangerous because we all know that people would just complain about that date no matter what and then take it as gospel and decide things are fine after that date.