One big issue I learned from my then colleagues:
Pineapple is just one system that is updated every now and then.
Robot is a family of operating systems, because manufacturers can and do tweak it for their own HW and UI. This has led to several funny (or less funny) issues over the years. Sunny has a lot different OS than Singsung than Two- than many others.
Banana is much more expensive (one manufacturer) and its pure number breaking performance is quite lame compared to Aliens, but as the system is just one, it has won many users, and coders (which means applications including HW).
With Papaya you most probably would have a working system. With the other, I wouldn't ever be so sure. And after any update anything can happen.
(I use both, because I have to use Fruit 12 Pro at work, and it is the worst phone I have ever had. One dealer started to laugh when he saw it, and asked have I managed to make any calls with it? Truth is: not many without WLAN. The same with email.)