It's impossible to "know everything about web development". That's not the point; nobody is demanding you become supreme master of every programming discipline.

It's impossible to "know everything about web development". That's not the point; nobody is demanding you become supreme master of every programming discipline. But by being afraid of dabbling outside your comfort zone (because mastering things fully is "hard"), you inherently restrict the solutions you can possibly even conceive of to an incredibly limited set. It's a sort-of Dunning-Kruger: You don't even have the basic knowledge to evaluate how often a better solution than "throw more javascript at it" was available to you and you didn't know it.