Robert Smeltzer, of Texas, held the record for most USCF (OTB) games played. I don't know who holds it now, he may still have the record. He would play rated games every night when possible, and often play two tournaments in a weekend. He passed away in 2010, but even though he played most of his chess long before the USCF database went on line, he has 8955 games credited to him.
http://www.uschess.org/datapage/gamestats.php?memid=11450342
Jay Bonin played [nearly] twice as much as that guy played
http://www.uschess.org/datapage/gamestats.php?memid=10098327
And that is only 1991-2018. I would expect a total of at least 20000 games by him. He is also an IM, not some 1600-1700 dude who plays chess every day just for enjoyment.
On a side note, he also played 4000+ tournaments, 1000 more then you mentioned.
Thanks! But you may want to hold your opinion on that for a bit longer (people around here have been known to chase me off with brooms).
That's a waste of good brooms.