I was thinking about how a lot of the front-page Reddit political posts seem like strawmen of the opposition, even more so when looking at specific communities devoted to one viewpoint or another. But if your exposure to right-wing arguments is based on videos of people like this, and the post is read as a response to those people, then they make a bit more sense. That said, just because I can understand why people would make posts targeting the lowest intellectual tier of the opposition, I don't think it's particularly useful.
Example:
Mathematician: I think I found a proof of the Riemann hypothesis.
Idiot #1: 1+1 = The Riemann hypothesis
Idiot #2: The Riemann hypothesis is true because Kim Jong Un said so.
Idiot #3: The Riemann hypothesis is true because astrology
Internet Arguer: Look at idiots 1, 2, and 3, and their terrible arguments for the Riemann hypothesis.
While the criticism from the internet arguer is probably true, it's probably more productive to answer the question of whether the Riemann hypothesis is true, you should probably respond to what the mathematician has to say rather than focusing on the endless supply of idiots out there. However, a lot of online forums are structured in a less than ideal way to prioritize clicks and don't allow the mathematician to rise to the top.
During Remy's trial, this line of thought occurred to me, because the defendant's posts all seemed like over-the-top strawmen, but he would link to rage-bait posts off the platform and say those were worse, and if I read his posts as a response to those, then I could see where he was getting this image of the opposition from.
Basically, I think someone will see people making strawmen arguments on r/politics and get downvoted when they try to respond/their comment gets buried. So they go to r/conservative to somewhere more aligned with them and argue against those arguments, but it comes across as a strawmen because people who disagree with them on r/conservative don't make the bad argument they're responding to. So those people call it a strawman and their comments get buried or they get banned, and the cycle continues.
I think places like DebateCraft or Discord or even real life can lead to more productive arguments. But I think people carry a lot habits from places like Reddit which causes them to strawman the opposition and often makes discussion more difficult. I've interacted with a fair number of people where they were using certain definitions or responding to certain arguments they assumed were universal and I had to clarify what their argument actually was before the discussion could move forward. I think a possible solution for this is when entering a new forum, don't assume your ideological opponents are as dumb as they were on the other forum, but this might be difficult to get people to stick to.