It has also been argued tape length limitations were Betamax's undoing. It was likely a combination of third-party support, practicality and content, each feeding each other... Turns out, people were content even with crap quality as long as they could cram 8 hours of stuff on a tape...
To a lesser extent HD-DVD and Blu-ray went through a similar "war". HD-DVD still has the superior menu system, but it had smaller discs. Anyway, IMO in the end it came down to content and device support.
Is EV charging in any way a comparable story? I don't know what the parallels and comparable lessons might be, but I think third-party support might be one. Who gets the inertia on their side and few can do it alone... Then again, a dominant-enough player can - it seems - successfully maintain its propietary standard: the iPhone dock/Lightning connectors.