The French government managed to rein in Amazon so traditional French stores, both online and brick and mortar ones, don't go bankrupt due to Amazon's unending pockets.

If they deem it necessary to rein in Google, they will rein in Google. There's no lack of tools for this, ranging from obliging phones sold in French territory to offer the French search engine as the default, to forcing every Google search result to promote the local search engine prominently, to campaigns about how it's important for national security not to rely on an adversary/enemy country's services, to everything in between and beyond.