By "it isn't in tech companies best interests to provide it"
They mean it isn't in Google's best interests to provide it. You can't data mine people's Gmail if it is end to end encrypted.
Apple could easily provide end to end encryption for emails between Apple devices, but if I use a gmail.com address on my iPhone and someone sends me an encrypted email from theirs, sure I can read it fine from my iPhone but would present rather a problem if I tried to use the GMail web interface instead. Even if it supported decrypting I'd need to provide Google my key which rather defeats the point of encryption when the biggest snoop on the planet has my key!
With Google permanently against such encryption and being one of the largest email players they have been and will effectively remain a roadblock to this. They knew what they were doing when they bribed everyone to use their service with a free gigabyte of storage, back when Microsoft was busy thinking they could monetize email storage.
Biting the hand that feeds IT
