Multiple people of similar height, weight, fitness levels yes. There can be a measurable difference and it can easily be as much as a medium to heavy workout, for the average to extreme ends of the scale.

Obviously someone who eats heathly, has a high percentage of muscle, exercises multiple times a week, will clearly burn even more calories than the same person who does none of that. What I am referring to is people who are close enough in these attributes and there still is a significant genetic difference.

This is very much genetics having an impact. It doesnt even cover the genetic difference between hunger sensitivity issues for things like insulin or GLP-1, which can massively impact dieting success.

I am not saying that environmental factors such as a life long poor diet and lack of exercise dont make this worse on top, but that genetics is a significant factor.

Second part is piggy backing, so apologies if it appears aimed at you.