I mean the article is about them building a 5nm fab in Arizona, so i assume they do need it if they want to build fast AI chips that compete with China should it invade Taiwan.
What process node Google uses for TPU, one possibility for an AI chip, is not in the public domain since v1 but it’s very unlikely this chip is on the bleeding edge. Cost/benefit is likely not there for this use case. But only Google knows for sure since they run the cloud and get to define “benefit”.
As I understand it there are reasons you want to not be behind in process technology as it makes your chips much faster. If your economy wants to keep pace I think this is a clever decision by the US government to entice TSMC to build a 5nm fab in the US.