My two cents
My two cents on the topic - and that is probably all it is worth.
Background:
I am a RF contractor working out in the Stix. My home county contains 17,000 souls and 860 square miles. Half the county is flat, and the other half has 400 foot elevation changes or is so hilly that it you stretched it out we would probably have over 2,000 square miles.
I am also a firefighter - belt, suspenders plus a spare rope just in case.
Local Public Safety is VHF-Hi, like our neighbors. My PS two-way infrastructure is dumb stupid old fashioned analog JPS-SNV voting. Seven RX Sites and four primary TX sites give me a reliable 90% portable coverage, duplicated over three channels. (Geek alert- I get full quieting with a mobile 0.20 uV in the air at all sites. Yeah, wow!) Backhauls are our own proprietary digital microwave. Each site has a standby generator plus 24 hours of battery backup just in case.
Ten years ago we committed to that infrastructure system because replacing many hundred existing mobiles and portables was not financially possible. Analog also has the advantage of playing "something" through interference. Digital systems - I do them also - are good, until any interference pushes the BER over the max and the radio remains blissfully silent. Not an acceptable situation if the interference makes one miss a "SHOTS FIRED" or "MAYDAY" message.
Fire and EMS paging for all eleven agencies is VHF-Hi analog tone + voice on one common channel. The system is not "Pin-Drop-Digital-Clear", but is reliable and within local budgets. Paging RF comes from seven old fashioned analog repeaters - not over the microwave links in case one fails. Plus, the central coverage TX site automatically repeats all pages after a 15-second delay for redundancy. This is our own one-way notification system and per NFPA carries no mobile traffic. Belt and suspenders.
Most agencies also get a smart phone app notification or text - the spare rope. Cell coverage is so spotty that some responders report getting the app/text after they are at the fire house putting on their gear.
The state's 800 P25 trunking system has 16 sites with county coverage, but portables still require a vehicle repeater to be reliable in a healthy percentage of the county.
We only have two significant cellular carriers but neither has smart phone coverage more than 80%. The two do not hand off between them, so while smart phones show service, calls are often dropped. The Sheriff moved their phone service to FirstNet - a great system IF AT&T has universal data-grade coverage - and deputies now report no usable service with alarming regularity. Hopefully that will change over time, but we are not on FirstNet's "A" list.
End of background and on to the OP's topic.
We have three analog VHF paging transmitters for three different carriers in the county. Grandfathered super-super-wide channels with very high horsepower ERP's, smack in the middle of the VHF-Hi band. One is a half mile from my home, and is so big and dirty it wacks out VHF reception across the entire band. Out of curiosity I set my SDR/PC to record and decode over a weekend. All of the traffic was phone numbers or alpha "Dr. X call ER" for a hospital 200 miles away.
One of my county RX sites is six miles and two miles away from wide-area paging transmitters, with a many-thousand-dollar RF filter system. Any test receiver pre-filter suite is useless from front end overload when either pager company transmitter is up. Mobile and portable radios in many areas suffer from the same issues. Even my coax-based cable TV and Internet signals are degraded when the system is paging Dr. X who is hundreds of miles away. (I cannot wait for Cable TV fiber hook-up coming the first of the year.)
I have worked with paging company field techs resolving interference issues. Nice folks, but tasked with patching together thirty-year-old equipment using only band-aids and duct tape. One problem was traced to an ancient RF filter can, and the replacement the tech brought was a take-out from an even older system. The jumper coax fell apart when he removed it, and he had no replacements on his van. (I donated brand new jumpers to get them running.)
Opinion: Paging companies no longer have subscriber cash flow to finance repairs and maintenance. I try to keep the equipment I build/maintain to the R-56 standard. At best, paging company's cash flow only lets them get to "R-5-point-6".They are not good RF neighbors to have. I suspect many other contractors have the same opinion.
Opinion: The wide area paging-only industry is dead. There are better alternatives, either a properly-maintained local transmitter for each hospital or cellular based service for when Dr. X is not nearby. Their time has passed and I personally cannot wait for the US to follow Japan.