Endodontically treated molars are over treated with destructive full coverage indirect crown construction, sacrificing sound tooth structure thus decreasing survival of the crowned teeth.
Provided the marginal ridges are intact in anterior or posterior teeth with a conservative access opening you can avoid full coverage restoration.. The tooth has sufficient strength to last long with permanent filling coronally to avoid leakage!!
You are saying that whenever one or both marginal ridges are lost then a full coverage crown is indicated, which I think is still destructive and the indications for full coverage crowns are less wide.