Well, I'm a firearm instructor, and up front, I'll say that if YOU are happy with what you shoot & how,, FINE!!!!!
But let's look at things from a few different points.
As noted,,, Bullseye shooters are shooting a specific discipline at specific distances, a specific way. And as noted above, look at the steel silhouette shooters. A totally different discipline with different ways.
Those are (2) excellent examples of ways to look at things.
But as an instructor, I break down ACCURATE shooting as follows.
The human body is the base platform. When standing we only have our feet touching a solid surface. If we sit, or kneel, we increase body contact with a solid surface. We stabilize the platform. Go prone & we stabilize the platform even more.
Next, the firearm.
One hand is the least contact with the body, while 2 hands have more contact. If shooting a rifle or shotgun, we also have the shoulder, & maybe a sling to add stability to the platform.
The steadier the platform along with the maximum contact available allows for better accuracy. It's noticed more at longer distances. When distance increases, and the targets get smaller, and accuracy is the desire, so you need the maximize the ability to be stable.
I taught a class this past weekend.
I always start new shooters at close distances & larger targets. Well, due to one student asking a question, I demonstrated a few different methods & added distance & smaller targets. They were quite impressed. And yes, one method I demonstrated was the 'Hollywood hip shooting" done by TV actors. I used a SA handgun, one handed, in .44 mag. But once I demonstrated all that,,, I also showed them what happens when you add distance. I used a one handed hold at 100 yds, & missed 3 times. I then switched to a 2 handed hold, at 100 yds, and hit all 3. I was shooting 8" diameter steel plates.
So, are you wrong?
NO.
Can it be better?
YES.
I like to call it all; "The variables!"