This shows how ridiculously irresponsible Google's decision is - to allow such a huge permission to be given via a single click in the same way as much less important permissions - and even worse, mixed in with other requests.
Alternatives they could have considered:
1. Don't do this at all - keep emails private and in your control. This is the sane solution. Make the user set up any apps with IMAP access as per a mail client. The friction here would make it much harder for the user to be deceived.
2. Allow it via the app permissions, but have a completely new approval screen for it to highlight just how important this is. The screen should have have a suitable graphic for a warning (stripes etc.) and say "WARNING - you about to...", following by a multi-click path to get around it. Then require a re-entry of password and TFA. Similar to Safari's certificate warnings when visiting websites [1].
3. Build an infrastructure whereby an app can access information without it leaving Google. A sort of sandbox/walled garden where the only ways in and out are strict APIs. So a company would be able to extract summary data, but not individual mails. Don't know if this is possible; depends on the use case. Would only be partially effective.
