Hardly "impossible to travel now without one." But they are handy...and don't leave home without the charger! LOL. And try not to leave it anywhere. While mine always ended up in casino security, it is another thing to keep up with.
I'm a step ahead of you, have a cell phone but have never installed an app. Texting is nice. GPS is nice. I don't use mine for email, afraid it will take over my life.
The discounts you might get at pizza places, stores, etc., are probably usually exceeded by your monthly cell phone bill.
If you've lived and vacationed to your specifications and enjoyment without a cell phone, that's enough.
But, if you get one, get an inexpensive small flip phone. Those have all features you need. I turned in my Trac Fone flip phone for a new android because my husband' friend said it was his preference over the iphone. I've regretted it ever since. Mine is so big, doesn't fit in all pockets, have to struggle to get it out of my purse when somebody calls.
But now all the companies have flip phones, which I will get if I ever switch.