I think it's processing power and engineering effort. I got a Sony RX100M2 for my mom and it has the same computational photography techniques that Google released the following year (https://ai.googleblog.com/2014/10/hdr-low-light-and-high-dyn...). But Sony's image stacking is only in "Superior Auto" mode, and is only used when necessary. Google's implementation does a lot of advanced work, including selecting and blending parts of the photo depending on motion, that Sony doesn't do. I assume Sony's imaging engineers have less expertise in advanced processing, and didn't have the resources to implement the features that Google did. Sony also has to devote engineering resources to other features - a lot of their sales are to photographers that will edit in post (RAW), and later, videographers. So features that are only in "auto" mode may have limited budget.