In this forum, this topic has been discussed hundreds of times. In fact, most of them discussed that they were different. However, for some reason, this issue is still being discussed again.
First there was stone, then bronze. Then copper came into our lives and then silver. The latest gold.
But if you've noticed, they all represent a mine and a physical element. Yes, it has mining in many crypto assets, but it is not a mining we know.
So please don't compare and think it is usefull for each other. And no, it can't. coins backed by cryptocurrencies is not a good idea.