I can vouch for this. It's amazing - one of these tiny 30W chargers, barely larger than the 5W iPhone cubes, powers all my devices. Especially coming from a huge Thinkpad charging brick, this thing is magic.
I have a PowerPort Atom 30W (about 1.5 inches on each side, or ~35mm.) It plugs into my M1 Air, and my iPhone charges off the Air's second USB-C port. Two cables and this tiny charger is all I need. There's a newer version, the Nano II, which is indeed slightly smaller, but some people claim that it has issues with various charging protocols so I don't see a reason to upgrade.
My only complaint is that for whatever reason, these don't seem to exist with EU plugs. There are GaN EU chargers, but they're not nearly as compact, which is disappointing. The US/China designs (the plug types are similar) are hyper optimized for every cubic millimeter, which is cool, but the EU ones are just the US/CN ones bolted onto an EU plug, which obviously wastes space.
I have a PowerPort Atom 30W (about 1.5 inches on each side, or ~35mm.) It plugs into my M1 Air, and my iPhone charges off the Air's second USB-C port. Two cables and this tiny charger is all I need. There's a newer version, the Nano II, which is indeed slightly smaller, but some people claim that it has issues with various charging protocols so I don't see a reason to upgrade.
My only complaint is that for whatever reason, these don't seem to exist with EU plugs. There are GaN EU chargers, but they're not nearly as compact, which is disappointing. The US/China designs (the plug types are similar) are hyper optimized for every cubic millimeter, which is cool, but the EU ones are just the US/CN ones bolted onto an EU plug, which obviously wastes space.