well investing in hardware is useless as the hw becomes old it has no value.
Those who invest in this don't seem to be aware of difficulty adjustment.
If someone is still thinking about this, please use this calculator before:
https://bitcoinwisdom.com/bitcoin/calculatorIf you put in BTC and have it sit there and mine, you lose. No question, you lost and it's gone.
If you day trade, however, it is far more effective than putting it in and letting it mine.
Cloud mining, if you just mine, is not profitable. But if you trade it can be, assuming you know how to read the market. I all too often see people who drop out of forex and come to Bitcoin complaining "Cloud mining isn't profitable!" when it can be profitable if you know how it works.
I wish people didn't think that Bitcoin is super easier than forex, and it just follows the same traditional rules. Kinda too bad.