Sexton already had gaudy counting stats in Cleveland. Yet there was absolutely no market for him when the Cavs dangled him in the trade market, trying to "sell high".
The problem is that he's not a winning player, and the whole league knows it by now. Here's a good overview on why advanced stats absolutely hate this dude:
The Cavs young star player Collin Sexton may not be the best option to lead Cleveland into the future if he doesn't develop more three-point shooting.
factoryofsadness.co
As I said earlier... as long as Sexton is starting and featured heavily in the offense, we'll be losing. I'll gladly eat my crow if I have to, but I have a sneaking suspicion it won't come to that. His negative effect on the play of the guys around him goes way beyond mere stats.