使用“defer”属性时是否有必要将脚本放在页面底部？

I always put my script tags at the bottom of the page since it's good practice to load scripts after things like HTML/CSS and text has finished loading. I just found out about the defer attribute which basically does the same thing, that is it waits till the page has finished loading before fetching and executing scripts.I always put my script tags at the bottom of th