An alternative implementation of BigQuery? If the integration libraries are that bad, perhaps the market would go for a BigQuery alternative with better integration support.

I expect that the integration libraries probably work pretty well for most users, and implementing a database like BigQuery would be a massive amount of work. So this pretty much explains why Google isn't sprinting to fix this issue.

Those companies are not willing to eat the loss though for whatever reason. If the company cannot be invested in it’s product offering there’s no reason a competitor to that product couldn’t successfully rise up. These are not mutually exclusive ideas as a competitor may inspire the company to pay due diligence to the product.

I think these opportunities in giant corporations are exacerbated where your competitor may very well be within the company itself.