I was curious to learn more about that claim about Hitler's origins, because Hitler himself explained how he became an anti-semite and I don't remember Schönerer appearing anywhere in that explanation. But the wiki link doesn't explain either. It just makes the same claim and cites a book from 2017. It turns out that book is readable on Google Books and it also doesn't provide any evidence for the claim of a Hitler/Schönerer link. It just asserts it without presenting any evidence or any further citations, in fact, the entirety of the argument is that Hitler was "no doubt" influenced by Schönerer. This is a worse level of evidence than a tweet.

Also you claimed Schönerer is the origin of the Final Solution but the Wikipedia page doesn't say that, so where did that come from?

I honestly wonder if Wikipedia should cite books. It's too hard to check those references so people don't and that lets un-evidenced claims get treated as "reliably sourced". Putting something in a book doesn't magically make it more reliable than putting something in a blog, yet Wikipedia's policy strongly assumes that it does.