system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: How does a hotel always have hot water for every occupant?
gpt
Some have really larger boilers and storage tanks. Others have multiple smaller instant boilers around the building.

Essentially the system is designed to handle the load.
Residential systems are often under powered or "right sized" for the owner that installed it, but that doesn't mean that sizing works right for everyone.