Should you quit smoking even though you've already been smoking for 7 years?
Better to not have started smoking, but still good to stop now.
The longer you go without giving new data, the less useful your old data will be. 6 months without new data? Not that big of a difference. 6 years without new data? Now that's a big deal.
If you found out that your mechanic had been ripping you off for the last 7 years, would you keep going to them for car repairs just because you'd already lost so much money to them?
It's not just about the practical aspects, it's about the principle. The big corpos make money from selling your data, do you really want to keep helping them make money off you after finding out how they do it?
Let's see how long it takes for this one to get discredited too.