I think HFT's have ruined Crypto trading for Retail but at the same time anyone , including Retail can get an HFT Bot to use on Crypto (the wild west) if they wish....some are free
It's not so easy to watch on an OTC stock with limited L2 but on a main board where they show all the orders and identify brokers you can easliy spot it and even figure out how much each broker is making an hour....and all done by a computer program