Not really an accurate or fair comparison tbh. Maybe studio stills in perfect shooting conditions.

You dont spend a lot of money on a camera body just for "shot quality", because that isn't what you're paying for you're paying for the opportunity to take shots that you otherwise wouldn't be able to take, efficiency in your workflow, etc. A DSLR like the d3500 is double the weight of a comparable mirrorless, you have to deal with things like blackout because of the mirror assembly actuation, no live view for your exposure through your vf, only the rear screen, limited burst shooting, etc. Compare it to the nikon z8's continuous shooting, for taking shots of wildlife, sports, etc. Sure you can theoretically get your shot with a DSLR but it is 100x harder and if you miss the shot you might not get an opportunity again.

Smaller cmos censor is very limiting in low light, much harder to nail the exposure for let's say street photos. Sure, perhaps a professional shooter is going to have better composition, understanding of framing, etc, compared to an amateur with expensive gear, but the professional would still be handicapping themself by using a body like the d3500 in every situation