… in other words, submit all of the data on your PC to Google to train their LLMs on.
It isnt as much as "omg, we need more data!!" but as some of the other comments show, it is _probably_ part of a larger defensive move where most LLMs are moving into controlling-the-pc domain. OpenAI has something, Claude has something, so it is reasonable to expect Google to do something as well. The fact that it is Gemini is another clue that it is indeed that.
Also, they are probably trying to figure out how to replace search traffic that switched to ChatGPT.