Eszett (ß or ẞ) is one of the prettiest Latin characters ever.

Capital Eszett

Traditionally, the ß didn't have a capital form. Words don't start with it. When one needs to type out a word with ß in all caps, they shall use the double S. In this way, for example, Preußen becomes PREUSSEN.

I think it breaks readability quite a bit, the same way Swiss German does it by not having ß altogether. The German word Maße (measures) and Masse (mass) look the same in Swiss German (Masse) or uppercased (Masse). For me, when I see ss I always read the vowel before it as short vowel. So, I would pronounce these two words in the same way.

Luckily, I don't have to, and neither do you. The capital ß, which looks like ẞ (absolutely gorgeous!), was invented at the end of the 19th century. In 2008 it became part of Unicode. On 2008-06-24, it got into ISO. And finally, since 2017-06-29, it is officially part of the German orthography. Amen.