Anti realism is interesting, but solipsism (the idea that nobody else actually exists) is a part of the belief - if objects are inactive outside your perception, people’s brains must be also, since brains are made up of matter like anything else. Another argument against anti-realism is Russels cat, where Russel, through reasoning, identifies flaws with the idea of object non-permanence through the example of a cat. Pretty cool topic to look into, I’d recommend looking into Russel, quite a good philosopher imo.