It's crude and useful, but not simple or infallible.
i remember a pilot saying "the radar is no good. The sky was full of cloud but the radar showed nothing" This was the first time he had tried using radar, and it prompted a general education on radar use. You have to search for data.
Radar only reflects off raindrops, and only if they are the right size.
In the central Australia we often get 'dry thunderies" which have lots of thunder and lightning but hardly any rain.
One of the American companies had radar specially made that operated in a different band to the usual (X band?) radar, and gave them different information that they considered more useful.
Like most things in aviation it's smart to gather as much information as you can get and then make decisions.
If you are in cloud with embedded CB's the radar information may be all you have. Or sometimes it may add to the information you already have.
I also like to cruise with lights low to keep getting information visually if possible.