I think one reason is that the internet makes it seem like things are easier than they are. You can browse the internet and in one afternoon see a hundred projects that each happen to be someone's life's work, and you are seeing them as a result of survivorship bias that has filtered out every project that was bad or unlucky or made by a normal person. The lizard part of your brain makes you think you can do a project like one of those ones in an afternoon even if you know better.