Code is probably just 20% effort. There is so much more after that. Like manage the infra around it and the reliability when it scales, and even things like managing SPAM and preventing abuse. And the effort required to market it and make it something people want to adopt.
Sure, but the premise here is that making a gmail clone is strategically necessary for OpenAI to compete with Google in the long term.
In that case, there's some ancillary value in being able to claim "look, we needed a gmail and ChatGPT made one for us - what do YOU need that ChatGPT can make for YOU?"
Those are still largely code-able. You can write Ansible files, deploy AWS (mostly) via the shell, write rules for spam filtering and administration... Google has had all of that largely automated for a long time now.