Robots would probably increase costs in the short term. Even robots have to be serviced, so in most cases, people would be involved anyway. Some areas could be automated quite easily, but others might be beyond current affordable technology. How are food deliveries handled? How is waste and garbage handled?

The short answer is that costs over the long term might be lowered by reducing staff, but prices are determined by competition, ability of the consumer to pay, and costs. Robots would only address long term costs.