C# 14’s field-backed properties are small, but I can see them paying for themselves in ordinary code. They remove one of those bits of boilerplate that is not hard, just repetitive.
The C# 14 docs describe the field keyword as a way to write property accessor bodies without declaring an explicit backing field. The compiler supplies the backing field, and the accessor can still do useful work such as trimming a string or rejecting a null value.
That is a good fit for validation-heavy properties. Previously you either used an auto-property and lost the custom logic, or declared a private field just to support a small setter rule. The new form keeps the property compact without hiding the validation. The important behaviour is still right there in the accessor.
There is one caveat: field becoming meaningful in the accessor can confuse code that already has a member named field. That is manageable, but it is another reason not to get theatrical with the feature. Use it where it removes obvious boilerplate. Leave the code easier to read than it was before.