If you want to watch the same content across several screens using an HDMI splitter you might worry about signal degradation.

HDMI ARC and eARC are useful technologies for streamlining your TV and A/V system's cabling, while giving you the best audio ...

In this case, a three-port HDMI switch is used with three inputs for source components and one HDMI output to the TV. When multiple TVs are used, there are HDMI switches with two or more outputs.