I have been a user of Google Home devices for several years now.
Recently my original Google Home and Google Home Mini have gotten where they dont hear my voice very well.
I have to get right up on the devices and shout.
What happens with these devices is that they tend to gather a lot of dust.
This happens especially if you have a humidifier running in your home.
To fix this problem, give it a clean with some canned air.
Youll want to focus around the areas where the microphones are located.
For the original Google Home, there are two visible notches on the top of the unit.
you might use canned air on them.
If that doesnt do the trick, try fishing the dust out of the notches with a toothpick.
Hit those spots with some air.
Cleaning these devices will often result in them hearing your voice better.