WordPress runs more of the web than every other CMS combined, and passes Google's Core Web Vitals on mobile just 38.4% of the time, the lowest of any major platform. The reason is loading, not responsiveness.
Source: PageSpeed Matters analysis of 3.7 million sites with CrUX field data, June 2026.
The single most popular way to build a website is the one least likely to pass Google's performance bar.
Source: PageSpeed Matters analysis, mobile 75th-percentile field data, June 2026.
The hosted builders control the whole rendering pipeline, so fast loading is the default rather than the reward for tuning.
Source: WordPress Passes Core Web Vitals Least Often of Any Major CMS, at 38.4% - PageSpeed Matters