To not confused you there is the aquarium co-op way of the fish tank and this is amazing if your focus is most tropical freshwater fish and the "natural biotope style" of the fish tank.
If you look at Cory's tanks he is using plants as another layer of filtering. Like Crypts, Anubias, guppy grass, swords, and so on. These can grow in hard or soft water or whatever water you have. The substrate is not as important
When you get to the more delicate plants you need to start moving from the "natural" aquarium way.
And look at how for example green aqua on youtube grow these plants. It's not as natural these are high-energy tanks where we try to help the plants to be the best they could be. It's a different style and I did both and both are fun just depended on the style of tank you are going for. But they have different needs and rules