A few possibilities.
1. The matter which can be discussed in the "special" forum.
2. He could have been 1814 back in 2019, 2020 or 2021 and hasn't played since. Some players do not touch over-the-board chess tournaments for a while.
3. His profile is inaccurate.
Personally, I think this person may not be very good, often have a quick discard or brilliant move, but there are also bizarre mistakes that people don't make, such as not eating after hitting double, which is very strange
Oh, the FIDE profile. I had thought you meant the Chess.com profile.
Could he have been playing on other sites or played over-the-board before he participated in FIDE tournaments?
I used to join one tournament when I was in high school. That tournament was my first rated tournament (to obtain a local rating - but this rating system is no longer existent). I was largely surprised by my initial 1723 rating. Some of my stronger friends obtained a starting rating of 1300+ and had wondered how I achieved a high rating.
(Sadly I dropped my rating afterwards to a final rating of 1603 before my rating vanished forever - but ironically I knew almost nothing about rating systems at the time of my tournament!)
And 2700 points is hard to achieve in three years, if he really has such talent why not go to OTB events and become a titled master
I suspect the player had been starting in casual, non-FIDE chess way before 2019 and had been grinding hard since then. A 2800 rating is still unusual though, but there is still that possibility of legitimate gameplay.
Maybe the 1814 was obtained because he wiped out all his opponents in a tournament full of low rated players (for example, a tournament for players under 1600 rating FIDE).
I suspect the player had been starting in casual, non-FIDE chess way before 2019 and had been grinding hard since then. A 2800 rating is still unusual though, but there is still that possibility of legitimate gameplay.
Maybe the 1814 was obtained because he wiped out all his opponents in a tournament full of low rated players (for example, a tournament for players under 1600 rating FIDE).
I looked at his record, FIDE, and saw that he had lost more than he had won, and it was very recent, which was suspicious
Since I had also heard of cheating in fast chess, and the system was very difficult to detect, there were engine mounts that could automatically move the chess, so I was a little skeptical
Hmmm...many different possibilities, but I suppose that other Chess.com players have reported the user for his unusually high rating. It might be what we really think.
If his play is actually sub-par in that club, reporting him might be a wise thing to do.
Actually he was on a national team, but his score was several hundred points higher than the highest bullet score, which was amazing
Yes, FIDE scores do differ from chess.com scores, but such a difference is rare at higher levels, most chess.com2800 players are FM,IM,GM, etc.
There is a difference between chess.com and FIDE, it varies from person to person, for example my netchess is not so different from otb (I mainly play online chess not on chess.com)
My ChessCom rating is 500-600 points higher than my FIDE rating!!! Dear ChessCom please don't ban me I'm not cheating on this website I swear 
!
This is an interesting and amazing thing, and in fact it's possible that people play FIDE less often, that they're nervous about playing and that the score isn't high, or simply that otb has less chess and that the score isn't up to par, but 2800 chess.com is indeed a very high and somewhat questionable score
2800 points on chess.com is an amazing 300 + in leaderboard,I don't think it's quite the same as 1000 + to 2000 +. 1000-2000 can be achieved in a short time, but 2000-2800 should not be so easy
This is an interesting and amazing thing, and in fact it's possible that people play FIDE less often, that they're nervous about playing and that the score isn't high, or simply that otb has less chess and that the score isn't up to par, but 2800 chess.com is indeed a very high and somewhat questionable score
Strawberry I'm curious what is your FIDE rating if you have any
As this is a personal question I totally understand and see a right for you not to answer if you don't want to
I found a person's profile on the website today, and I was very confused. His FIDE is only 1814 points, but he has a full 2800 chess.com points. He plays chess against different opponents, but with high accuracy, even blitz and bullet have more than 80 points. Could you please explain this matter? Thank you
By the way, his profile says he learned to play chess in 2019, and his account was set up in early 2022. FIDE and Chess.com's blitz and bullet both have only 20 or so games saved, and all the chess on the sites are from 12/27,28,29