First of all, the industrial and jewelry value of gold is so far below the current market price, that if suddenly everybody decided that gold was only worth its utility value people holding gold would lose almost everything. The difference between 95% and 100% is really negligible.
Secondly, on power consumption, the whole "one transaction requires more energy than a house" is basically sophistry. Even if this number wasn't overstated, it's stated in a way that assumes that this is static, that buying a coffee costs a house worth of energy.
No matter whether you are a Bitcoin person or a Bitcoin cash person, the number of transactions per unit of energy in no way will stay the same. If you are a Bitcoin person, you will see the lightning network, which will increase transaction throughput by several orders of magnitude, and if you are a Bitcoin cash person, the block size will increase continuously, shoving more and more transactions per block.
Thirdly, the claim that you can't convert Bitcoin into cash is simply stunning. I use Gemini as an exchange daily, and I've witnessed $1 million being liquidated into US dollars in a couple of hours without much slippage.
Finally, I would ignore the final paragraph because this person has shown that he knows absolutely nothing about Bitcoin or cryptocurrency.