Great work, did a similar analysis recently but only for the top 50, and in fact none of the top 50 had an EV at the time of the survey.

I believe the only possible advantage of an EV is not a technical one, but rather an organizational one: it encourages the use of a unique keypair on each server because Wildcard coverage is not allowed (although multi-domain is allowed). For what appear to be non-technical reasons, I have seen many entities copying their keypairs for Wildcard certs between servers, even between business critical on-prem backends and cheap shared hosting or budget VPS, or handing the keypair over to a contractor via email.