Google is a patch work family where the siblings constantly fight each other for their parents' favor. All the teams are competing for promotions and money that you get through "impact". Go and Dart are just like all the other Google products that get released with much fanfare and then quickly forgotten once their creator's no longer need them for their next brag sheet.
What we need is a crowdsource project where we dedicate gpu resources to build a model from scratch. There are thousands of us in here, and thousands more in the wide community.
Open-assistant.io is what you want.
They've gotten more than 100k RLHF training dataset and is actively tuning up a Chat model based on GPT-NeoX (?) from what I've heard.