There is no single Yahoo EOD. There are TWO sources and TWO methods: Yahoo HISTORICAL and Yahoo CURRENT that differ, see: http://www.amibroker.com/kb/2007/08/04/amiquote-and-free-data-from-yahoo/
You are apparently comparing apples to oranges (Yahoo CURRENT to Google EOD). Google EOD is comparable to Yahoo HISTORICAL - it downloads one symbol per request but allows to download more than one day. Yahoo CURRENT was downloading JUST ONE day, and many (upto 200) symbols in one request, hence it was faster, but these two are uncomparable (serve different purposes).
AmiQuote support for Tiingo is now covering also multi-day downloads with speeds comparable to Yahoo EOD.
Yahoo CURRENT (single day update for many symbols) will be functionally replaced by Tiingo CURRENT. Support in AmiQuote for that new mode is in the works and it is fast, since it uses pretty much same method, i.e. multiple symbols in one request.