Music theater singing is foremost about telling the story. The story telling is "out front", the voice is used to project the text in a way can be understood. Many singers are capable of using their voice in this medium, especially with the now common use of the mic. What is often misunderstood by the performer, is that the role of the mic cannot substitute for the source of the sound. Good Intonation is needed on the part of the singer, as is breath control and an understanding of vocal technique on demand. The mic is not there to substitute for vocal ability. If the system goes down, or there is a short in your mic pack, your voice should still project. Your job is to produce your vocal sound consistently, so the sound engineer can efficiently balance the board.
The shift away from a theatrical lyric style of singing to the use of commercial styles of today's pop, rock, hip-hop, etc. has created a problem for the performer. Consider this comment made to a performer at an audition by one of the creative team of the Queen musical We Will Rock You “It sounds quite nice. It’s actually quite riveting,…but it sounds like it needs to hurt more.” Theater singing is not the same as what is achievable in a recording studio. The studio recording environment which often builds the voice using post production enhancements and autotune is not at all the same as the performance demands of eight live shows a week. The stresses are even greater if you are performing on tour, as the environment and climate can change often, and the physical strain of travel is added. No one will care about your vocal health more than you do, and it ultimately is your responsibility to know what your voice can sustain under great stress. Knowing how you must use your voice so that you have the best chance of remaining vocally healthy is the foundation provided by owning your vocal technique. Your voice is part of your actor's toolkit, maintain its efficiency by studying regularly.