The second one above is not Apple (and depending on the source, the first one may or may not be).
Also see the following from Fast charge your iPhone X, iPhone 8, or iPhone 8 Plus - Apple Support
Fast charging gives you a quick and convenient way to recharge your iPhone X, iPhone 8, or iPhone 8 Plus. Your iPhone fast charges up to 50 percent in 30 minutes when you use an Apple USB-C to Lightning cable and one of these adapters:
- Apple 29W, 30W, 61W, or 87W USB-C Power Adapter
- A comparable third-party USB-C power adapter that supports USB Power Delivery (USB-PD)
There is no (or very little) advantage in having one larger that 29W.
From Apple: 30W USB‑C Power Adapter - Apple