PoE is for powered endpoints
Buy PoE when cameras, ceiling access points, door controllers, or other endpoints need both data and power from the Ethernet cable.
Power budget beats port count
A switch with enough RJ45 ports can still be wrong if the total PoE wattage is too low for the access points or cameras attached to it.
AP uplinks may need more than gigabit
A Wi-Fi 6E or Wi-Fi 7 access point can benefit from 2.5GbE uplink. Many budget PoE switches still provide only gigabit ports, so match the switch to the AP uplink.
Security cameras may need VLANs
If camera isolation, guest Wi-Fi, or separate smart-home networks are part of the plan, a managed PoE switch may be better than a simple unmanaged box.