Magnesium glycinate is even better. Glycine turns out to be important too, but it's just used as filler.
But yes, glycine also has many of its own benefits. Including a very interesting theory regarding life extension due to its interaction with methionine. [2]
[1] https://examine.com/supplements/glycine/#nutrient-nutrient-i...
[2] https://www.fasebj.org/doi/abs/10.1096/fasebj.25.1_supplemen...