Platforms that offer greater freedom also tend to host visibly more extreme content. My guess is the slightly more advertiser friendly extremism pushed by algorithms on mainstream platforms is far more impactful on society.

Outside of the relatively small number of people engaged with issues like software freedom, privacy, right to repair there is no reason to choose a platform with less views unless your content is banned from the alternatives.

I expect Rossmann's politics are shaped by his experiences as a small business owner. Many such people desire greater economic and individual freedom and are likely economic liberals but that doesn't necessarily influence their views on other matters. He is an outspoken advocate for consumer freedoms including right to repair which I respect. I don't know the guy personally but I would be surprised and disappointed if he endorses far right crazy shit. I am using Lemmy and respect the people who wrote the software but nothing about my politics should be inferred from theirs.