A couple of things:
There aren't too many Americans who don't receive mail at home. That means they can send mail from home as well. The postal service isn't going away, it's just being streamlined, which is long overdue in our modern day and age.
The delays and screw ups in mail delivery aren't "recent". They've been going on at least my whole entire life, and I am 56 years old.
The "news" media is choosing to focus on this because they want you to think Trump is killing us all. Post boxes were removed under Barack Obama as well, but you didn't hear a word about it and it didn't impact life as we know it. That's because it's a non-issue being used for political purposes by the lying fake news biased media.