Should I keep HTTPS Everywhere if I use a VPN?

Hi, I've been using HTTPS Everywhere for around 6 months now on Chrome and Mac. I really like the idea of it, but sometimes I wonder if the service actually works, since the certificate seems to drop at times on popular websites already with https like YouTube. Also, I was wondering if I run a VPN service, is the extension even necessary?In this case, is HTTPS Everywhere redundant? I currently use IVPN. Thanks.