While in mining there is a risk that the site will close or not pay dividends because of the difficulty, I remember that it was this explanation that genesis mining gave when the bitcoin price dropped to $4000.
to be fair that can not be called "mining" because people who use "cloud mining" services aren't really mining, they are just giving their money to someone else who promised them they were actually mining but the reality of all cloud mining services for many years has been that they were Ponzi schemes. some might have had some real hashrate but that doesn't change their Ponzi structure since that has been the only way for them to make any profiit.