With NPAPI each site picked one plug-in that worked in multiple browsers. Another site could pick another single plug-in that also worked in multiple browsers.

With NPAPI each site picked one plug-in that worked in multiple browsers. Another site could pick another single plug-in that also worked in multiple browsers. With EME, each browser supports some DRM(s) and there's no single DRM supported by all browsers, so sites need to support multiple DRMs to reach multiple browsers.