Cellphones can be tracked. Walkies and pagers can't.
If I were the IDF, this is the communications system that I would prefer the enemy to use.
Walkies transmit sporadically, so they can be tracked when activated. It's not instantaneous, but with a decent logging system you can keep track of users to a large degree. Even when you have multiple units all of the same model on the same frequency, there are various tricks to sorting them out to individual units.
One-way pagers don't transmit typical signals, buy like all RF devices, they're still emitting some signals and are trackable to a large degree with an antenna network deployed for that purpose. You might not be able to track them deep within enemy territory, but there is still a lot that can be done to track general movements or to find where clusters of the oscillators associated with the pagers turn up in large numbers.
At least with the pager attack, Israel hasn’t directly admitted it was behind it. Even though pretty much everyone knows it was them. But kinda hard to deny missile attacks.
EDIT: I meant walkie talkies. Old school pagers probably can't. Also I guess if you just use walkie talkies to listen to instructions. The station broadcasting can be tracked, however.
The pagers in this case were very boring POCSAG receivers, no transmit capability.
One can triangulate a radio broadcasting, I don't know how one would track receiving the broadcast.
A lot of worksite-oriented handheld radios these days are not just oldschool FM and use digital protocols to efficiently manage bandwidth, which can involve transmitting when not actually sending voice data. I haven't seen any confirmation of whether the affected devices were digital or not, but if they were buying COTS radio equipment there's a decent chance that they were.