No one has a $3m Google Ads budget for something that doesn't work already. I've run campaigns for brands that lead the market and for new businesses that have no brand recognition at all--the difference is night and day. Should founders run to Gmail ads because of this? Probably not.
Assuming the campaigns are still profitable, doubling the budget is great. I hope they really did well. But what does this really tell us? What can a startup or small business founder learn from this? Not much.