I buy solely Android flagships these days (and we just shelled out for one for my wife), and I'll tell you why. I've been burned multiple times by mid-range Android phones - both personally (old LG smartphone) and indirectly (family buying mid-range smartphones). It's not worth the daily frustration of living with a device that constantly lags, hangs at random times, making it difficult to use with the standard suite of apps (mail, maps, social media) and sometimes making it difficult to answer a call. This is death by thousand cuts, it really takes a toll on your psyche - particularly if you use your phone a lot.

Buying a flagship is pretty much a guarantee that you won't have to suffer through this, and will have a device that's reliable for years. I used my Galaxy S4 for years (replaced broken screen two times, and broken camera once; had luck of doing that when I was in Shenzhen, so it wasn't even expensive). When I switched, the device was still better in use than a new mid-range phone, so I gave it to a family member, who used it until it died of mechanical damage. I'm on S7 now, and it still doesn't show signs of age - and I expect it to live and perform for couple more years still.

Flagships may seem overpriced, though if you calculate in their longevity and mostly-frustration-less experience over whole lifetime, I'm not sure if the price is really that bad. So I prefer to save up for one, instead of going for mid-range phones that magically tend to start breaking after couple months of use (P8 Lite, I'm looking at you).