Letter (at least some) that we should think about restoring to English

Eight years ago, I wrote an article about the letter thorn, that used to be used in English to represent TH sound.  Before that, I wrote about even more common sounds in English that aren't represented by English letters. Well, a few years ago, Austin McConnell also covered this topic in his video 10 Letters We Dropped From The Alphabet. In particular, my mind was blown at learning the origin for the name of "&".

Out of all these letters, I think we'd benefit from the restoration of thorn, and maybe some modification thereof so that the voiced and unvoiced TH sounds can both be represented.  (Much like Austin, I'm not a fan of eth.)