I spent us$10 😱 for ERC for my eur10 KAS2. If it happily falls again on bottom not lens, I will justify this expenses. Oh, and ERC included KAS which I don't use for now.
All in all, I don't adore cases (there are nicer things to adore) but they make RF's easier to carry than naked camera. Thicker? Most of fixed lens RF's need soft release too, which makes them also taller! 😛
SLR (evil ones) are different - they don't need any cases. Naked, with neck strap - to loop it around hand. "People are strange", aren't they?