The contents are simple. How to interpret the contents, is not simple. That is why you seen internet advice advocating for keeping old raw files around, because Lightroom and Photoshop sometimes gets updates which can cram out better results from old raw files.

(Edit: I mean, if you want to get a basic debayered RGB image from a raw, that's not too hard. But if you want to cram out the most, there are a lot of devils in a lot of details. Things like estimating how many green pixels are not actually green, but light-spill from what should have been red pixels is just the beginning.)