Phonics is an intervention that works – at least in Bethlehem, PA, where the portion of kindergarteners testing at benchmark increased from 47% to 84% from 2015 to 2018 as the District moved from “whole word” to phonics instruction. What's more, every kindergarten in the District showed marked improvements, with similar gains regardless of 2015 performance and regardless of the percent of students who are low income. In the graph below, vertical distance above the red line indicates gain in percentage points.
Phonics remains controversial among educators (as does Whole Word). For a good read on this topic, see this article from APM Reports.