I've always considered Bitcoin to be something of a Ponzi scheme
As opposed to the Ponzi schemes called USD, EUR and the like? Please, before you criticize an alternative to old systems, try learning something about the old ones first. You might find there was something wrong with the old scheme, and hence new alternatives were proposed.
I wonder what will happen when the computational power required to feasibly mine bitcoin exceeds the limitations of what cutting edge semiconductor processes can deliver.
Next, try learning something about Bitcoin itself. Basically, what matters to your income and influence on the network is your _proportion_ of the total computing power of the network. There's no absolute requirement to worry about.