As I have read noone exactly can answer this question as there are 2 opposite opinions on it. Btw I think the opinion that mining is worthless is more popular than the opposite opinion.
Mining is not worthless, it supports the blockchain and secures the network. Without mining, there is no Bitcoin.
The correct question is "Is mining worthless for the home user to ROI?"
If you only have a few hundred or a grand or so to spend, yes it's worthless.
It's an arms race right now, and many of the home miners are exhausting getting new circuits installed, and you're slowly seeing a shift to the datacenter for cooling and electrical needs.
It's like the old saying "Don't bring a knife to a gun fight". Biggest and most power efficient Asics win. Unfortunately, it costs significant amounts to keep up.