In my experience people arguing for data lakes talk a lot about some unspecified future benefit. Companies typically want to learn things about their interactions with their customers that allow them to make more money, and thus GA or its equivalent represents the 80/20 — or more likely 80% of the benefit for 1% of the cost — solution.
Your statement implies a lot of assumptions about a business’s model. Our company cares about user interactions in our app, software development metrics, quality metrics, sales metrics, etc. GA is just one small piece of the puzzle.
“Data lake” may not be the right answer, but GA certainly isn’t.
