When you charge an iPhone with a USB-C to Lightning cable, the iPhone only draws the maximum power it is designed to regardless of the size of the power adapter. It doesn't draw more power or charge faster with a 96 watt or 140 watt power adapter than if you used a 20 watt power adapter.
Also see the following from Fast charge your iPhone - Apple Support
To fast charge, you need an iPhone 16 or later with a USB-C cable, like the one that came in the box, or an earlier iPhone model with a USB-C to Lightning cable and one of these adapters:
- Apple 18W* or greater USB-C Power Adapter
- A comparable third-party USB-C power adapter that supports USB Power Delivery (USB-PD)
...
For iPhone 15 and earlier, you can fast charge up to 15W with a MagSafe Charger and one of these adapters:
- Apple 20W or greater USB-C Power Adapter
- A comparable third-party USB-C power adapter that supports USB Power Delivery (USB-PD)