Of course, there remain areas with zero to horribly poor cell service,
making cell cams a no go for those areas.
But at the time of new purchases, keep in mind most cell cams work the same as most traditional trail cams, and you don't have to use the cell feature. Some cell cams are actually priced cheaper (at time of purchase) than their comparable non-cell traditional trail cams.
I often discontinue the cell feature on some cell cams afield, say in May, and those cams simply continue working as a traditional trail cam until I go retrieve the sd card. May go "service" one of those, say in October, then finding out what happened there between May & October, restarting the cell plan with a new sd card & new batteries in October.
Leaving out cell cams for long periods of time, such as year, can necessitate higher capacity sd cards than are useable on some brands. I'm not buying any new cell cams that won't accept at least a 64 mb sd card. If you're running video, you may need at least a 128 mb card.