The abs must be trained on everybody. They are so important for producing force, absorbing force, protecting the spine and organs and keeping performance high plus injuries down.
Just lifting and doing planks isn’t enough for athletes and active people.
Stabilization is important but after an initial General Physical Prep phase of training planks become easy and we use them more in a warmup.
To really strengthen the abs you need to resisted movements and sometimes pretty heavy!
Spread Eagle Sits Ups are tough and train the Rectus (front of abs) and the hips very well and because of this we use these quite often!