Something like that or better said: in these two countries were freedom and democracy are not particularly appreciated the need for a “backup communication network” are much more felt as a priority up to necessity. In both cases the “regime” of the two countries is aligned also with the security of the nation even if - unfortunately - it is not their main concerne.
This is an auto-referential paradigm.
It is a well-know fact that the market let win weaker technical solutions…
For example, despite the Microsoft Windows NT kernel was designed to compete with the best in class OSes, it never reached the masses but Win95 → Win98. The MS-DOS was a pale resemble of IBM-DOS in terms of technology but was much easier to copy because the lack of protection on the floppy disks. Piracy does the rest spreading around the one which was similar in functionalities but easier to copy. The GNU hurd micro-kernel was a promising technology but the student Linus’ monolithic kernel took the place in the heart and in the x86 HDs of many.
Technical superiority wins only in small niches which requires that superiority to exist. The SFOS is not a mainstream solution, obviously and to affirm itself in its niche should bring a sort of technical superiority but because it aims to be installed on smartphone - it should also complains with the end-users market dictatorship. This is the reason because they moved their business in a niche: automotive. It is the wrong niche, IMHO.
Returning on the 2G/3G shutting down: the telecom companies have a clear interest in left behind a commercial obsolete infrastructure to increase their savings/returns and/or investing in the next generation technology or expanding the current. Obviously, they do no care about the nation security which can be affected in many different ways or in a special cases like Switzerland just a little.
Moreover, the regulators usually do not have any specific advantage to intervene and being hated by these large and somewhat powerful companies. Until the day an emergency on a vast will hit the country and shock the people. At that point they will leverage the emotional wave of the nation to spend taxes in build a backup telecommunication network that they let commercial companies dismantle.
Build - destroy - rebuild. A market/business mantra: instead of supporting an obsolete technology, destroy it and the re-sell again as a national security technology at added value price the next time for the sake of deep pockets states.
Not in Hungary nor in Italy because their regimes fear too much a “time window” of insecurity not about natural catastrophes but because possible riots. Usually when a riots in a large area took place the 3G->5G services will go to be shut-down and 2G remains only for voice coordination among the repression forces. Under the PoV of the regime is an emergency to deal with as efficiently as possible in case prevention countermeasures did not succeed enough.