because everything you see can be manipulated, especially things made by man. They can be made the way man wants them to be.
Look at YouTube and compare it with other video hosting services like Dtube, Rumble, Vimeo Odysee, etc. It has turned into a bubble of false reality that people who use it don't know about. Many still don't know videos are removed, deboosted, and promoted based on what reality YouTube wants to curate. The same is true about social media. Many who use those spaces still don't know that their feeds are not random or solely based on their interests.
This is done in real life, too. School is a top-down controlled false reality, which is why people who succeed in schools don't succeed in real life and vice-versa. In school, students succeed by bootlicking and rote learning. Neither works in real life. In real life, you need talent, one thing that school never teaches about. In school, decisions are made with control and obedience in mind. Talented students are refused opportunities if they are not obedient. In the real world, decisions are made with profits in mind. Therefore, the free market puts more money on talented people, not necessarily certified people.
A fake reality can also be carved off the real world. Look at our medical establishment. People think that drug-based treatments provide the best healthcare. This is why they live in fear of medical costs and pay for health insurance. They have no clue how well-developed and often well-advanced traditional medicine, naturopathy, and other holistic sciences are. How has such hypnosis been accomplished? The ruling class put money towards education, where children are brainwashed to love drugs and think of all non-drug therapies as quackery. Then, publicly funded higher education subsidized the education of drug-based medicine (not healing). Then, medical boards and licenses were established. Soon, doctor started to mean someone who prescribes drug-based therapies, not someone who heals. This definition of doctor took out the healing part. And now, real healers are not even considered doctors. Today, people think it is normal to take drugs when they have a cold or a fever. They think anxiety and depression are largely medical conditions (read Thomas Szasz if you are curious). Those who intuitively disagree are called insensitive if they intuitively disagree.
The physical world is not all fake. It is generally an accurate reflection of physical reality. But man-made reality can be very fake and can put you in all sorts of delusions. Look at the trail of money. Money is used to artificially make people do things. Whenever money is being used by a centralized entity that does not have to be accountable, a false reality or multiple false realities are being created. Those who are in the bubble are often clueless though they are bound to experience depression and anxiety because their intuitive side wouldn't believe the false paradigm. They would try to kill their intuition to rationalize what they see. This would manifest as different kinds of psychological illnesses.
"Don't believe everything you hear: real eyes realize real lies." --generally attributed to Tupac Shakur.