The purpose of using a urethane or epoxy is to create an impermeable and seamless floor. This provides a much more cleanable surface for when chemicals are spilled.  If you have VCT in these spaces the chemicals can easily seep through the seams. These coatings are also chemically resistant, preventing toxic chemicals from destroying the floor. Typically, these floors will have troweled base cove which prevents anything from getting under traditional vinyl cove.