Calorie restriction becomes much easier when you're substituting calorie dense foods with more calorically sparse ones. It's hard to continually fight the hunger caused by just eating less over time.
The epiphany I had with this was that when you want to substitute "calorie dense foods with more calorically sparse ones" AND also get in enough nutrients, that you are basically shifting towards a WFPB diet (the type of food mankind has been eating mostly, for most of its existence)
"Whole Food, Plant Based", for those who had to look it up like me.
I'm more of a "eat food, not too much, mostly plants" kind of guy, I'm not willing to give up meat, eggs and dairy. Which people have also been eating since forever.
But I agree that a lot of people are way over-complicating nutrition.