Even you say those are legit companies for cloud mining, it doesn't change the fact that your profit from those cloud mining sites will continue decreasing, probably because of the so called maintenance fee,
In the past, most cloud mining companies have been outright scams, frequently via some kind of
long con. I expect that in the future (along with the cloud mining companies that presently exist), most cloud mining companies will turn out to be a scam.
Even if you could somehow
guarantee that a cloud mining company was not a scam, it would probably not be a good idea to "invest" in a cloud mining contract. I will list some of the reasons why below:
Additional Middlemen need to profit:
When you buy a cloud mining contract, you will almost always buy from an entity that is not the manufacturer of the mining equipment. This means there will be at least one additional entity that will need to charge a markup in order to turn an expected profit. If the cloud mining company advertises, the price you pay for a cloud mining contract will need to be increased in order to pay for the advertising expenses.
Cloud mining companies will have difficulty scaling:
Normally, very large miners can find efficiencies in their setup to reduce unit costs, however, this generally takes some trial and error. Cloud mining companies will generally need to "lock in" their expected costs when pricing their contracts to customers to ensure their operation is not unprofitable. If a cloud mining company were to find efficiencies after they initially sell their contracts, they would not pass those cost savings onto their customers, but they have little reason to look for those additional efficiencies, as they would already be operating profitably.
Similarly, very small mining operations may sometimes be able to find unique discounts that are only available to very small operations, for example, a datacenter (sublease) may have a limited amount of space to rent at a lower than the otherwise normal price. Or a small miner may have a unique situation in which they can procure a limited amount of electricity that is free or that has a lower than market cost.