When you say "nobody installs it that way", that is not true for large multi-AP systems. Those are designed so that there is always some overlap between APs. Otherwise you'd have dead spots.The laptop is designed to connect even if the channels are different so a star system effectively gives you the same wireless results.
If an AP dies, whether its backhaul is Ethernet or Wi-Fi, yes the STA may try to roam to another in-range AP. But I'm discussing the AP's network connection.
In a similar way, a mesh leaf node with Wi-Fi backhaul to another leaf node will try to connect to another leaf node if the one it is connected to dies. If the leaf node re-establishes connection back to root quickly, the STA will have no reason to move to another AP.