Nope. The real risk (assuming its not a scam) is future difficulty and btc exchange rate (operating costs are in still paid in fiat)


But you cant know what future profits will be like. You make assumptions on exchange rate and future difficulty and those assumptions tend to be overly optimistic. If they predict a significant profit, that very same prediction will lead to increased deployment of hashrate which will invalidate your prediction. In a sense, its a self defeating prophecy. To some extend the opposite is also true, if even the most efficient mining operation can no longer break even on its running costs, then difficulty will adjust until it does, because less efficient miners will unplug.

In short: long term profitability of mining is just marginally above zero for those with the most efficient hardware and the lowest operating costs. No need for math or estimates, its just how this market works. Its a zero sum game after all.