The internet is just a small world where a user eventually be disappointed to one casino and will look for another but this user may not be going to a casino with bad reputation. If the user find out there is one casino like 1xbet that is totally a suspicious casino, he will avoid this casino at all cost.
But there may also be some casinos to avoid especially the ones with recent scam accusations. It doesn't even have to be true that this casino had scammed users. They just need to spread the word is a scam but just a false accusation.
Online companies spend fortunes in writing bad reviews about their competitors. It's shady over here and only the strong and competent business withstand all false accusations layed on them. Established casinos may not focus on hitting upon other gaming platforms. But these kind of war could be expected from newly launched casinos looking to attract players in every possible way. Although when it happens like Op described, it won't be an open fight, the attacks will begin from top review sites, which may later be figured out as false.