I could certainly live without being able to adjust the size of the icons, but what I'm most interested in is something like the start page for Safari 13, which has larger icons than Safari 14 and 15. I like that their larger size makes them easier to click. But the main thing is being able to set a specific number of columns so I can organize it how I want, with icons in specific positions. It's quite annoying that Safari 14 and up changes the number of columns to fit the width of the page so that you can't rely on things being in a predictable place.