I really don't know y samsung is not providing screen recording feature in m21,m30s,m31.. which is basic feature of android 11, exynos 9611 processor is enought to use screen recording function but dont know y samsung do this.
In flagships we have it, but only records screen no audio source. But, stock android provides both screen as well as audio. To samsung: If you are removing a feature to put your own, at least keep the basic features same.
