Hey @aichja,
Welcome to the Forums!
It is recommended but not necessary to reboot your network. If you feel like you start to experience a slower connection or higher latency as time passes, then the reboot schedule is recommended.
Wi-fi routers all have a memory just the same as a phone or computer does, over time, this memory may fill and decrease the performance of the network. When the router is rebooted this will be wiped and the network will have the entire allocated memory to work with. The reboot will also clear any settings that may have been causing interruptions. Essentially, it will do the same thing to your network, as a reboot does to your phone or computer. Placing the reboot on a schedule simply means that it is one less thing to worry about.
I would honestly recommend attempting to configure the setting, and then observe if any of your devices have issues reconnecting to the network. If devices have trouble reconnecting, it may be well worth your time to either set longer periods, or disable the feature and reboot manually when you begin to feel the network slowing. Devices reconnecting to the network have always been the issue that prevents me from rebooting more often
As for how often, I think it would be dependent on both the amount of devices connected to the network, and the bandwidth used by the connections; as these will both affect how quickly the RAM is used on the router. If you have only a few devices, your network may only need to be restarted on a monthly basis; whereas a network approaching the maximum number of connected devices may have to schedule a weekly reboot.