NB-IoT is probably where your application would go these days. Bi directional communication, cheap chips, and data plans around $10/device/year for 12MB [1], which is a lot of short messages (though things like OTA firmware updates might be painful).
I am not opposed to using more efficient network protocols, more that we are endlessly replacing old technologies with completely new systems. The selling point of 3G/4G/5G has been that they will have more bandwidth, so people can watch videos or use self driving cars.
What is more interesting to me is embedding cheap low-bandwidth smarts in more devices. The costs of the new and immature hardware gets in the way of that.
In the cellphone commercial sure but in technical reality it's about device density. There is only one set of airspace and only certain chunks are useful for where we want to communicate; getting the most devices able to communicate has been the leading driver of RF planning and design for quite some time now. Bandwidth usually materializes out of a combination of more "slots" to talk and simply not using restrictions needed for 20 year old consumer hardware.
I agree that at this point the cost of cellular IoT is higher than it should and the technology is immature. In the long term though, it would be a better choice than keeping a 2G network.
Also, firmware updates for these devices are a few KB typically and occur maybe once every 6 months. 12 MB per year should be enough.
NB-IoT is fine, I will have to use it. The cost of 4G/5G chips is a lot higher than older generations, to say nothing of what would happen if anyone can make chips.
Everyone just wants to sell me something new, because that's how they make money. When 3G came out all the telecoms were excited to sell video, as it would give higher average revenue per user. Turns out people don't want to pay more.
We get faster networks but keep the same price per GB, so with 5G I will be able to blow through my monthly bandwidth in 60 seconds. And that assumes that the carriers have the backbone capacity.
[0] https://www.avnet.com/shop/emea/products/quectel-wireless-so...
What people are telling you is that 5G is more than just a plot to sell you YouTube streaming. It is the only way carriers can scale the mobile network to meet its growing needs.
There are only so many ways you can cram more people into a shared medium like the RF spectrum....