I would say that any company that has 45 million customers is doing pretty good. 10% definitely makes many companies the largest in their sector, not every company is a Google or Amazon that’s completely consumed it’s market.
Maybe. I could see sites removing access to less profitable users, probably in lower income countries to stay below the 45 million threshold. Or perhaps boot low-engagement users in order to keep user-counts below the threshold. When regulation exists with a threshold, enterprises will strive to stay below it. Hence why there's such a huge drop-off in businesses with 50 or more employees in France [1] [2].
That could still be an improvement. It would mean that the reach of those sites can't grow beyond 10% in the EU. Other sites would then pick up the users that were left out.
If you drink one cup of coffee a day, that's less than 10% of your waking time, but coffee is systemic to your life.
If 10% of your cells have a defect, that defect is systemic to your body.
If your API is down 10% of the time...