In theory perhaps it's no different. But I think EME would work out very poorly in practice. Some browsers either allow no plugins or only a few grandfathered plugins. What EME systems will they support? Imagine a future where Mobile Safari only supports FairPlay, IE only supports WMDRM, Chrome OS only supports Widevine, Android gets fragmented into a half-dozen different DRM schemes depending on vendor, desktop Linux has nothing, etc. This scenario is much worse than Flash.