Long covid deniers are science deniers. I suggest they search out the data, then argue with the scientists. Or perhaps they have a problem with simple math.
But consider these: 1) any one who has a case of covid that lasts longer than some reference time length, say perhaps 2 weeks of illness ( or make up your own number and tell us why, I had to pick something to get the party started)
2) If you die that is long (forever) , so add 800,000 plus dead in the USA alone.
3) have a gander at world o meters
https://www.worldometers.info/coronavirus/country/us/ note changes by the minute with updates.
USA currently has 10,309,361 active cases. That equals all the cases since September 7, 2021 until today. In and of it self that seems long.
Now obviously some of the people who tested pos since then have recovered or died, so many (if not most) of these cases are from even farther back. Remember some positives are asymptomatic or hardly sick at all.
The current infected number is probably a reasonable MINIMUM approximation of long covid cases. [On top of that some long covid cases have been resolved by now. ] Without the resolved long covid cases it still comes out to about 20% of all infections. Not counting the dead.
How does any rational person equate that to some misguided notion along the lines of 'hardly anything'?