If it was the whole story, they'd put their own content (the rare ones for which they have 100% of the rights) with no DRM and the maximum resolution. But they don't do that.
In some cases you might get 720p (Netflix content) instead of 540p (third party) with widevine L3.
In some cases you might get 720p (Netflix content) instead of 540p (third party) with widevine L3.