I find that my smart phone has made several things more convenient than previous semi-smart and dumb phones, so that I do them more. Not that any of those things are necessary, but it has lead to extra enjoyment for me and (hopefully) for some others as well. I don't expect any of this to impress Tom, but it does speak to his "why" question:
Some of the more convenient functions I use (in no particular order):
1. I text more and more often because the keyboard is easier to use and the "smart" keyboard makes typing easier.
2. I snap photos of interesting or whimsical things and send them to close friends/relatives whom I believe would be interested
3. I occasionally add events and photos to our Facebook account to keep friends advised of what we are up to
4. I look up trivia immediately when a question arises in conversation, e.g. "what was the name of that actor who played...". Not at all important, but fun in a social setting.
5. When shopping for anything at all I can and do price compare instantly.
6. I check weather forecasts as needed and also get severe weather warnings for my immediate geographic area (because my smart phone knows where I am via its GPS and also via the IP address). I think this is really valuable function for an RVer or anybody who travels a lot.
7. I carry a lot of photos with me now because the screen is large enough and the images good enough to make showing others a reasonable thing.
8. I use the phone to listen to and identify broadcast music that I have forgotten the title of or the recording group or whatever. Great assist for my failing memory...
9. When I find myself waiting around somewhere, e.g. a doctor office, I whip out the phone and start reading one of the several e-books I have stored there.
10.I use the Flashlight function every once in awhile. Maybe about every 6-8 weeks. Handy to have a flashlight in your pocket at all times.
11.I use a Shopping List app to help me remember what I went to the store for, something that is increasingly necessary for me.
I could do many of these on my previous semi-smart phone (aka "feature phone"), but it wasn't any where near as easy or quality, so I seldom did it. Therefore I have to say that the smart phone "enabled" me to do more.
adding a few items:
1. App called "gas buddy" shows where fuel/gas stations are located on a map centered on our current location with prices of fuel. The fuel prices have been updated, often hourly, by customers using the app. So you can find stations and prices easily.
2. Voice search for "whatever"... for instance, if you are in a new city and want to find a CostCo, do a verbal search and in 10 seconds or so, you get a map and directions to the store... or restaurant, or grocery store, or repair shop or wh, atever
3. draw app: amazing app that allows me to make a sketch of anything using the touch screen, save the image, print the image, etc
4. engineering calculator/unit converter: instantly recall many engineering constants and make unit conversions as needed.
5.financial apps: fidelity, credit union, banks, etc... get stock quotes anywhere, check orders, do transfers, etc
6.internet forums: lots of forums have mobile apps
7.twitter app: nuff said
8. TED app: listen and view TED talks
9.Google apps: instant contacts sync; email sync; calendar sync;... many others across PC's, phones, tablets, etc
10. moblle hotspot app: modem/router for other computers as needed
11. golf gps app: instant distance from your location to the front, center and back of the green at any golf course in the country
12. 500,000 other apps on every conceivable subject you can imagine. just go to Google play and do a search of apps.
13. angry birds apps: endless entertainment by the angry birds... crazy
14. news apps: endless
15. eBay/ amazon apps: shopping, info, streaming movies, tv shows, cloud storage of documents, sell stuff
16. travel apps: make reservations, check availability, see photos of sights,
17. Verizon wireless app: check on phone minutes used, data used, bills, etc
you probably get the point... other people probably have much longer apps lists