Comparing google to big tobacco is very flawed. Big tobacco has essentially one product, and that product is always harmful.
Google on the other hand has a variety of products. Even when it comes to their biggest product i.e. ads, they'd still make a shitton of money without tracking and storing everything in perpetuity. Would they make less? Very likely.
But they will not "stop existing", even if they were forced to stop all tracking tomorrow. They can still sell ads not based on the users tracking history, but based on other context that doesn't require a huge data store, but ephemeral information at most (e.g. "user is searching for term x RIGHT NOW, and has a German IP RIGHT NOW"). And of course they can still make money from the "play store tax", money from users of their APIs, cloud and services.
If we actually prohibited tracking now, far beyond what even the GDPR does, advertisers would still spend money, like they did in the print and television days as well. And google controlling a large part of the market already with an iron grip (search, youtube, android) would still come out ahead of the competition.