Unflattering fake images of politicians have been around since people first learned how to draw and paint pictures. When photography was invented, it wasn't long before people found ways to fake photographs. Computer graphics made things easier, and modern professional image editors and so called "AI" powered graphics programs have improved the quality of fakes beyond what's possible to someone with a home computer and photoshop.
Only the gullible (mostly but not exclusively Biden voters) will believe everything they see on the internet or on the TV news. The biggest issue is confirmation bias - if it fits the desired narrative, people will accept it as fact, even arguing for and defending it.
