What they did
Google published a guide on managing crawl budget for large sites. It sets out which sites should read it and which can skip it entirely.
What they found
The guide tells most site owners not to read it. It aims the advice at sites with more than a million pages that change weekly, or sites over 10,000 pages that change daily. Google calls the page counts a rough estimate, not exact thresholds.
How much weight to give it
This is first-party documentation on developers.google.com, so it carries weight as a statement of how Google approaches crawling. For small and medium sites it is a clear steer that crawl budget is rarely the bottleneck.
What it doesn't prove
It describes crawling, not ranking, so a healthy crawl budget won't lift positions on its own. The thresholds are approximate and the page is revised over time.