Recently I showed somebody https://search.feep.dev and they opened the browser network tools and went “Where’s the XHR? Where’s the JavaScript?? How did you change the URL?”

They had no idea that <form><input></form> is all built in to the browser and you can make GET and POST requests without any frontend code. (Not that this is a new problem, <a onclick="document.location='...'"> has been a thing for decades at this point...)