Apple battery pack is not meant for full charge. It's for convenience & double up as a magsafe charger when u plug it to a 20W charger. Many ppl can't justify to buy it la. But diff ppl have diff needs. Plus lazada flash sales at $90 i think can consider. If retail $139 then no go.
Agree with you
on a technical viewpoint, most people would say its not worth it given the capacity and charging speed. which I totally agree on it and in fact, MagSafe battery pack would totally be eliminated from the list if comparison is made in this manner...
But what we are buying is more of a power bank that's around 65g, most are around 110g, that could be easily slot into the left pocket of your pants, without bulging out looking weird, sufficient enough to have a peace of mind in knowing the phone would last you through midnight to book a grab home, the very least.
having it act as a MagSafe charger is a plus, though no entirely needed, its able to synchronise well between both devices towards the sweet spot of heat efficiency and efficacy. at the end of the day, I'll have a full ready battery pack with me as long I stick it to the back of the phone when I charge it, and not a dead portable battery when I'm leaving the house just because I forget to charge it.