I held off on Windows 10 for as long as I could until Adobe, and therefore my job, required it. Now this nonsense. I hope this isn't the start of them joining on the web DRM bandwagon.
Flash was pretty significant in the web's journey to where it is today. For things like online video, it was the least pain in the ass way, in a time when the alternative was crapware plug-ins like RealPlayer, QuickTime, or Windows Media Player.
YouTube probably wouldn't have existed without Flash and FLV.