Yes, there is plenty of evidence. One quick way of getting some of it is by actively seeking out those sources which are being blocked and checking their "credentials" (i.e. checking out their work more than which school they happened to have gone to). The scientific method can not function when part of the discussion is suppressed, for whatever reason.
Also, nobody states that all contrarian ideas are being suppressed. The discussion here is on the subject of SARS2 treatments which are being suppressed.
Do I know whether these suggested treatments work? No, I do not. Neither do you. The reason why none of us knows this is because discussion on the subject is being suppressed, not because there is evidence of these suggested treatments being ineffective. A good example of this is the recent disclosure of the combination of hydroxychloroquine and azithromycin leading to a doubling of the survival rates of ventilated patients [1]. The paper is interesting, the discussion following the paper even more so. It is this discussion which should be allowed, not suppressed. This discussion should not consist of solely criticism of "this paper is not peer-reviewed" or "this paper has not been published in a major journal", the discussion should instead be had around the subject matter. Peer review and journal impact measurements are means to an end, not ends in and of themselves. I'd like to see the same type of paper and discussion around e.g. the efficacy of ivermectin and/or fluvoxamine, out in the open, without accusations of quackery, without politics, without interference by commercial interests.
In short, I want the scientific process to work as intended.
[1] https://www.medrxiv.org/content/10.1101/2021.05.28.21258012v...