The questions I get most often at JamesGames all start, "What's the best…?" There is, of course, no such thing, because every gadget from phone to camera to tv set is a compromise, a balancing act, between competing criteria.
There is no better proof of this than the myCharge lines of battery chargers, any one of which might be "best" for you, but totally wrong for your friend.
They have models for those who prioritize charging speed, the Razor line. Then they have the ruggedized Adventure line, where durability is more important.
Before the pandemic, I was a traveler. And myCharge had the perfect line of chargers for me: the Turbo Hub series. I tested the Hub 10050 Turbo Portable Charger ($99)
Almost everything I needed to power my gadgets while I was on the go is built in. The integrated iPhone Lightning™ and USB-C cables are built in, plus there is an addition USB-A socket if you need to use different cord, say a USB mini. This means I don't have to worry about forgetting cables in a hotel room or digging them out of my travel bag when on a plane. Ingeniously, you don't even need an adapter to recharge it; a fold down plug goes directly into a power socket.
The Hub series comes in a variety of sizes, depending on how much power you need. Additionally, there are models that promise faster charging. The Turbo model charged my iPhone 11 Pro in about 50 minutes.
Of course, even the built in cables are a bit of a compromise. Of necessity they are short. This means you probably won't want to use them at the same time as you're trying to hold the phone to your ear. The solution of course, is to carry an long USB cable, but then you've defeated one of the built-in advantages of the design. The unknown question, one I haven't been able to quantify, is how rugged are the integrated cables? I've had units like this from other manufacturers where the cables broke long before the battery refused to take a full charge. I've tried to give the myCharge Hub a workout, and the connectors still seem as solid as they day I started several months ago.
This unit has earned a place in my travel bag, serving up power-to-spare (upwards of 50 hours!) and spare-power when and wherever needed. Highly recommended.