You as the developer have access to and are aware of all possible display dimensions and aspect ratios. It's not that hard to prioritize the sizes you want to support and then work based off that. There are plenty of tools out there that let you simulate different screen sizes for testing too. I don't see this information providing any extra value.
But you are assuming the users browse the website in full screen mode/maximised. Whilst true for most mobile devices, this is certainly not given on desktops.