How exactly do I compare a smart phone sensor to a handheld regular camera of any sort? I've seen the DXO scores, but from memory the smartphones are only compared to smartphones, and regular cameras only to regular cameras. I use to assume the numbers they give are interchangeable from phone to regular camera, but then doubt set in and I wasn't sure anymore.

Yes I realize the regular camera like a top line Sony is likely much better than the top of the line smart phone. I'd just like to know by how much better in image quality. I have an iPhone X and I usually shoot in RAW on that phone. I have several Nikon DSLR cameras and they are heavy and I don't like to carry them when I'm traveling. I've thought about mirrorless a bunch of times. Though if the iPhone X on RAW is seemingly good enough and it is already on me, I don't care to carry another camera, unless there is a strong reason to. I did recently buy a GoPro Hero 7 and I've learned to clip it on my backpack strap and put it on time lapse photo at 30 seconds interval. And so far I love it. I get so many cool random photos when I go hiking. I liked the GoPro so much that I recently just bought a gimbal for it and I also strap that to my backpack strap, because the hundreds of unlevel photos is a pain to fix one by one. Anyway, point being, I would carry a mirrorless camera if I thought the image quality was a lot better the RAW on iPhone.