The Russians don't have reliable communications, so it's not like there's that much choice.
Furthermore, the level of training and education of the average Russian soldier is.. not great. Look at some of the things they did around Chernobyl for an example of their knowledge gaps. Same goes for their discipline ( low morale, poor training, corruption, encouragement of war crimes will do that).
> The Russians don't have reliable communications, so it's not like there's that much choice.
Oh come on, VHF radio is stupid reliable. It's a war zone, so nobody's enforcing TX power limits. I don't buy this explanation. They aren't downloading multigigabyte 4k video, they're issuing combat orders. VHF has done a great job with that for decades.
Have you seen the captured kits? Some soldiers have cheap walkie-talkies (literally commercial off the shelf cheap Chinese brands), but many others have nothing.
If i recall correctly, their aircraft are supposed to be fitted with some high tech super encrypted communications system, but it doesn't work, which is why they use phones (with buttons).
It's not a matter of "the tech is too complex", it's more of a "the people supposed to implement/acquire/rollout this relatively basic tech pocketed the money instead".
Probably the superiors did not waste time explaining the reason and just demanded their phones, then the Russian soldier stole or robbed a phone and called home since he knows there is a big chance that he will be dead soon.
So if you think that your soldiers have this need to talk home maybe an competent army should offer them some alternatives, like some satellite phone they can use once a day and call home, you can't expect 18 years old forced to go to war to be professionals.