Combat healing in DnD games has always been suboptimal use of precious action economy since early editions (not sure if 5e changed it much) given the relative weakness of cure options until Heal, and the risks involved in applying said healing (aoo's/disruptions). If given the choice it's almost always more efficient to use your turn to do something that eliminates/reduces threats (kill/damage foe, cc, debuff) or enhances the chance of NOT needing healing (in combat buff NOT precombat buff).

Healing is a last resort that you do if you fail to do 1 and 2 quickly and efficiently enough. It means you either have very suboptimal characters, bad tactics, or your well planned tactics went sideways (which certainly can happen).

This is known.