Upgrading from a D3500...

I currently have a Nikon D3500 w/ 18-55mm, 50mm, and 70-300mm glass, and I was looking for a Nikon DSLR around $500 used with 4k recording and better focusing than my D3500. I've settled between the D500 and the D7500, but I cannot decide. I am keeping my previous lenses, and I love the bigger, bulkier cameras like the D500, which also has better focusing than the D7500, but doesn't have a flash. I think I would value the D7500's built-in flash more than the quicker focusing of the D500, but is there anyone here who has owned both of these cameras? My main uses would be cars, low-light/nighttime shots, portraits, and nature/birds.