I don't feel that it "is letting me down".
I had been a PC/Windows user for decades. Hated it. The MacBook changed the way I use a PC and the overall experience as well.
What concerns the iPhone and iOS. My first device was a 3G. Loved it. Some time ago decided to try Android (phone and tablet). The tablet was a disaster with time, no updates at all, apps stopped working with the older version of OS, regular freezes, reboots etc. Nevertheless, I have to admit that both Android phone and tablet provided freedom a geek like myself needs time to time. I enjoyed it, but numerous problems (stock e-mail and SMS client shortcomings etc.) forced me to come back to iOS. Yes, it is a closed system compared to Android, but it is more reliable and safe (for me at least).