About Reddit, they have more users and major traffic from the United States, then the UK and Canada, and then they are also popular in India, Brazil, Germany, Mexico, France, Australia, and the Philippines.
If you are not in any of these regions, Reddit will be very unpopular.
In other words, Reddit is a geotargeted social network, which means it can only be beneficial when you need to attract an audience from the above-mentioned countries. But in this case, it is strange why many gambling platforms still continue to create their accounts on Reddit. Given that many gambling platforms have country restrictions due to licenses, it's strange to promote your brand in such a social network.
I would not like to say that they do not know that Reddit is only popular in certain regions because gambling platforms usually have a very strong team that engages in serious market research before they enter any sort of project for marketing or promotion. They know the statistics and most likely are okay with it.
Gambling Platforms and casinos may not have a worldwide target, but certain regions, so Reddit works properly for them.