Unlike tight hamstrings or chest where the cause and effect of tightness is fairly obvious tight ankles aren't as obvious. But it is a fairly common one. Tightness in the ankles manifests itself in other ways, knee pain, forward lean in the squat, lack of depth
etc. So it's not something that's easily identified.
When you can visualise what additional flexibility in the ankle area will give you, the benefits are clear as day.