There are 2 professional poker players on this site that I know of.
Inevitably you will get a couple of other charlatans with about 10 posts, claiming that they are as well, such is the nature of the poker ego.
What you need to understand is there is a constant flow of people cycling through the system, many of which after winning a couple of MTTs will think they are capable of playing professionally. 99% wont be and will fade fairly rapidly when the cold streak comes.
You can play the exact set of tournaments ever day, and you'll be amazed at the through-flow of people throughout a year, but the core always remains. They make their margin from the throughflow, not from each other. 85% of online players have a negative ROI%. This is where the money comes from.
What you should also understand is that the majority of online pros make their money through volume, rather than through high-rolling.
It might be volume in cash, it might be volume in SNGs, or it might be volume in MTTs, or often a combination of 2 of them. Most will have a key game, which they rely upon, and it is virtually never NLHE, (unless it has rebuys).