I switched back to a flip phone between using an iPhone 4 (before) and an iPhone 6 (after), when iOS updates made the 4 slow to a crawl. I decided I was "done"

I switched back to a flip phone between using an iPhone 4 (before) and an iPhone 6 (after), when iOS updates made the 4 slow to a crawl. I decided I was "done" with smart phones. There wasn't a major disadvantage that I remember, however the killer app that made me come back (and buy an iPhone 6) was Uber/Lyft.