I noticed something while comparing final images from LR Classic, C1, and Luminar 3. The file sizes were different from each editor. The LR file being the smallest around 12mb. C1 around 22mb. And Luminar 3 at 30mb. All were edited as closely as possible, using the same color profile at output.
Not 100% sure of this but I seem to remember that some cameras at least save files to a standard size 'envelope' while others more closely follow the actual pixel count. Not sure about different software but it's an intriguing observation.