Yoga and stretching both increase our flexibility. However, while increased flexibility is a benefit of yoga, it's not the main purpose.
Yoga Anatomy Lab: The Lats
Hip Mobility Exercises: Internal and External Rotation in Yoga - YogaUOnline
Strength versus flexibility in yoga — Dynamic Yoga Anatomy
Yoga anatomy fundamentals for yoga teachers – Sampoorna
How to Create and Maintain Truly Open Hips on the Yoga Mat
Hips: Yoga Anatomy for Strength and Mobility
Working Your Edge: Stretch Tolerance On and Off the Mat - YogaUOnline
Yoga Poses for Tight Hamstrings
Flexibility And Stretching In Yoga - Yoganatomy
Bridge Pose Yoga Stretch - Video Guide