Can actually answer this one.
Reddit has a fairly sophisticated metric for rooting out bots but there's one really, really fucking simple workaround. Buying already "confirmed" accounts. The more important, the less chance it's going to get nuked, et cetera.
This has multiple levels to it. The first level, the bots that are a few dollars to cents, are the ones that are going to be used for vote manipulation. As it goes up, you end up with higher and higher gay ops until you reach the peak; which is outright political shitposting.
A few years back I followed an account I first saw in 2018 post nothing but essentially political posts against some random dude running in Georgia. He was on the front page of like, 30 subreddits for the two weeks before then fucking vanished. His account was like 8 years old.
Millions of people saw those posts. It was without a doubt, a stroke of fucking genius on the person who pulled it off. For presumably under the price of a billboard, this dude got who knows how many people aware of how fat and how little sex people wanted to have with some random dude in the running. And it was all done for under the price of a billboard.
The scrubs make the accounts. They sell them to the fixers. The fixers take orders from whoever pays them.