Comparing smartphones to communicators is a bit like comparing trains and 4x4s. While one is sleek and modern and offers a wide variety of personal choices in luxury, it is useless without the extensive infrastructure which needs to be laid out well in advance (people always seem to forget about the mobile phone masts!). The communicator is more like a satellite phone which, like the 4x4, may be less pretty and multifunctional but does exactly what you need it to do, wherever you need to go.
If course, modern satellite phones are getting smaller by the year, so the TOS communicators are looking more and more and more like oversized toys:
Ah well, never mind