I have 2 routers of the same model in diifferent locations, one on EE and one on Three and the one on Three requires far more reboots which is why I thought it might be carrier related but I guess it's possible there are other factors.
The Netgear Aircard I used needed rebooting most days.
The Huawei B525 has never been rebooted by me in the last 3 months. However within the options it does have an option enabbled that states it will restart the router weekly if it deems it necessary. I assume that being there means that restarting router weekly can be needed in some circumstances. Although, a reboot on the B525 only takes seconds to reconnect even when forced. By default this happens in the night, so even if it is doing this, i wouldn't notice.