The getter-for-everything pattern in LWC templates is now optional.
Where
Lightning Web Component templates. Opt in per component in the .js-meta.xml file; requires API version 66.0 or later.
How
Write expressions such as arithmetic, string concatenation, ternaries or method calls directly in the HTML template instead of exposing a getter for each formatted value or pre-mapping loop data in JavaScript. The virtual DOM diffing behaves the same as before.
Why
Simple display logic no longer spreads across two files. Components get shorter and easier to read, and the opt-in flag means nothing changes for existing components until you decide.