You do realize votes don’t actually have any value right? And I have yet to see any community on lemmy ban account based on downvotes, this is just something you’ve made up here. There’s a reason why lemmy has a public mod long where you can see the reasons for bans. Show me a single instance of people being banned because their comments were downvoted.
Yes, people will try to push agendas, and this is nothing new or exclusive to social media. The real problem with commercial platforms is that a private entity controls the content on the platform deciding what people see using opaque algorithms, and introducing biases into content that benefit the company running the platform. That’s why corporate social media is so problematic. Again, you can compare wikipedia as an example to see the huge difference between an open and transparent platform compared to closed private ones.
There is simply no actual evidence to support your position I’m afraid. Mastodon network is literally millions of users now, and anybody who uses it regularly can see a drastic difference with corporate platforms.