The Game Review estimated rating is just that, an estimate. The process takes the ratings of the players and the associated accuracies and presents a value. If the ratings of the players in the same are modified, the estimated rated will change.
That value isn't saying you're a X rated player. That's not what those values are.
Your opponents are other members that have created accounts and if you think any of them are using disallowed resources you should report them.
https://support.chess.com/en/articles/8562517-how-do-i-report-someone
Finally, the site also does not hack your computer or purposely slow down your client. As a basic member, ad code can cause increased load though. There are some things you can do to make the experience better.
https://support.chess.com/article/4720-online-chess-performance-optimizations
I am not saying the players are cheats, the website is a cheat! Why? I have no idea. Probably to frustrate and annoy players. First you must realize that most of the so called opponents are actually bots. That's a fact, now, my rating is around 1500 for Blitz. That said, I often get analysis that says my rating is around 2200 for individual games with 90% or higher accuracy. So, please tell me how I can play this well can get crushed by a 1400 rated player? In fact, I have played 99% accuracy and barely won on time with over 60 moves played in bullet against approximately 1450 rated players. That is why I say the website is a cheat. Simply put, if the ratings were correct I shouldn't be able to hit 99% accuracy and still nearly lose to a 1450 rated player.
Now, if that alone weren't enough, I have evidence that Chess.com hacked my computer. For one, they caused my computer to run slow while playing blitz games, making the pieces move around weird. Now, if I am simply playing someone else, what is the cause of this slowdown? The site also caused my screen to turn off during games several times... never happened before. So, please tell me, what in gods name is causing all that to happen? Is it because Chess.com is hacking my computer and cheating to cause me to lose games? STAY AWAY FROM THIS WEBSITE!!!
Response from control: We have already hunted down and killed everyone involved with this website... This is why it is rife with hackers, nobody is in control anymore. When the hackers hack this website, we hunt them down and kill them. This response was written by the control, please accept our apologies for any disruption to your computer chess experience. Thank you!