Reset state without Effects using key - reactjs

Question

I came across exercise from beta.react docs concerning issue: Reset state without Effects.
You may find it in the bottom : Challenge 3 of 4: Reset state without Effects.
There's a component that receives object of person data to present it in editable form.
As for start it tells you that useEffect is redundant.
import React, { useState } from "react";
//ExportContact.jsx
export default function EditContact({ savedContact, onSave }) {
const [name, setName] = useState(savedContact.name);
const [email, setEmail] = useState(savedContact.email);
// useEffect(() => {
// setName(savedContact.name);
// setEmail(savedContact.email);
// }, [savedContact]);
return (
<section>
<label>
Name:{" "}
<input
type="text"
value={name}
onChange={(e) => setName(e.target.value)}
/>
</label>
<label>
Email:{" "}
<input
type="email"
value={email}
onChange={(e) => setEmail(e.target.value)}
/>
</label>
<button
onClick={() => {
const updatedData = {
id: savedContact.id,
name: name,
email: email
};
onSave(updatedData);
}}
>
Save
</button>
<button
onClick={() => {
setName(savedContact.name);
setEmail(savedContact.email);
}}
>
Reset
</button>
</section>
);
}
Suggested solution is to split into another component that will receive key of contact id.
Like that where EditForm contains everything EditContact had so far.
export default function EditContact(props) {
return (
<EditForm
{...props}
key={props.savedContact.id}
/>
);
}
I'm just wondering how would it be different to add key prop with contact id value right into the parent component like this:
<EditContact
key={selectedContact.id}
savedContact={selectedContact}
onSave={handleSave}
/>
Instead of splitting EditContact into artificial subcomponent only to receive a key prop.

Answer 1

The difference is explained in the official link about spread attributes.
Below is the official summary:
Spread attributes can be useful but they also make it easy to pass unnecessary props to components that don’t care about them or to pass invalid HTML attributes to the DOM. We recommend using this syntax sparingly.