Agree with all the people saying stuff like this. Imo it's cool when it's to emphasize tone (like when people use a smaller font for a few words when saying something shyly?? Hope you guys get the idea lol). But when it's the whole post it's just hard to read and I end up just skipping it. I could see myself completely skipping any posts that have mostly decorative or colorful fonts. This would be a cool feature as long as we can turn it offI feel like the font and thread customizations have the potential of already worsening readability (there are people who type in the smallest font possible while using colors that are hard to read ) and it looks like staff have already responded to a similar thread about semi-permanent text formatting options with a hard no...
I think for island journal decorations, it might be nice though!! but definitely a hard pass for me on general threads. I already have a hard enough time reading small letters and can't imagine trying to read a busy typeface at that size...