Not correct. “Free” memory doing nothing is bad. But “available” memory is memory being used by the system that can be easily freed is a good thing. 
Or officially:
Available memory: Estimation of how much memory is available for starting new applications, without swapping.
Source: man free
As per the screenshot below, free memory is just about unchanged. So nearly all of the system’s memory is being used. However, the system will swap less now because there’s more available memory that can be freed when needed.
…yes, I prefer to free up memory if not being used until such time traffic requires any changes.
thanks again.