A lot of people mess up more by doing a maintenance calorie estimation wrong and relying on it rather than counting calories coupled with weighing themselves and adjusting calorie intake up/down depending on whether they lose/add weight... If you use a feedback loop, then indeed it doesn't matter if your calorie estimate is anywhere near correct anyway, as long as you're reasonably consistent and the errors aren't too badly skewed toward the wrong foods.
I did this. I targeted 0.5kg loss per week, and since 1kg of fat is 7000 kcal that meant 500 kcal deficit per week was needed.
I measured my weight every morning (after peeing) and wrote it down, and used it to compute weekly average.
I did weigh ingredients for the first couple of weeks to get an idea, but after that just did rough estimates coupled with tuning based on feedback from the body weight every week.
Had a near perfect linear trend for the year I did this.