BTW Square your question is backwards.
The question isnt on the concept of chazaka. chazaka is mentioned before the idea that ” that there is nothing to be taken for granted, and teva is as much a neis as a neis nigleh, ” (though nobody that I’m aware of says this is “all what Judaism stands for” )
the question is on THOSE sources, how can they say that when clearly the Gemara based on pesukim (veyatzah hakohei min habayis…) says there is a concept of chzaka.
to that you can answer as DY has. but the question you posed is backwards