“what are often called facts often turn out to be an illusion”
You are way too nice.
History has shown that almost everything homo sapiens believed was total and complete garbage—designed by the elites and their witch doctors to keep the masses ignorant and the elites and the witch doctors in power.
I have seen no persuasive evidence that it is different today.
The more (real) pure research that gets done, the more previously unknown things are learned, and previous views must be dumped. The idea that knowledge is mostly complete is itself a fiction.