https://www.theverge.com/2019/3/4/18250583/google-pixel-3-march-update-camera-storage-fixes

Google’s March security update for Pixel phones also includes some much-needed functional improvements for the Pixel 3 and 3 XL, as noted by Android Police. The company seems to have heard complaints from users about its latest phones becoming sluggish over time — especially the camera app. This month’s update promises to improve startup times and general responsiveness for the Pixel 3’s camera app.

The March update also “improves storage performance on Pixel 3 devices,” meaning Google has been able to further optimize read and write speeds for the phone’s flash storage. Someone posted screenshots comparing storage performance before and after the update, and it does seem like a nice improvement.