apple 20w adapter

FYI ... The iPhone's "charger" is built-into the phone itself. These would be power adapters. If they are Apple adapters, then it really doesn't matter which on you use. Depending on the country you reside in, a "3pin" adapter would indicate that it would have a ground. As such, this one would be "better" to use with your phone.

Would you please post images of each of these power adapters and both cables you mention?

Apple cables should already be MFi-certified. If your 3-pin cable is MFi-certified it should be of equal quality.

What am I checking? That these are genuine Apple power adapters? It appears, from the images, that you have a mix of ugreen & Apple products.

You also are showing me that you have Type C & Type G plugs, so not exactly sure where you reside, but that doesn't really matter. What would be important is that the Type G plug is grounded, where as the other one is not. Typically, you will want to use grounded outlets for safety reasons.

Regardless, there is no way I can tell you which is better. As I mentioned before, the actual "charger" is built into your iPhone ... and it is what regulates the amount of current it will accept regardless of the power adapter you use. It is normal for the phone to get warm when charging. However it should never get too hot to touch when doing so.