Personally think Google should get rid of them as they are a travesty to online privacy.
You install Google Analytics precisely to track where users are going.
You don’t install a Google Chrome extension so a company can track every site you are visiting.
It would be interesting to know the names of these chrome extensions and whether the sign up experience clearly communicates the ways in which the users will be tracked.
At some point I should be allowed to trade my personal information in exchange for goods or services, isn't that the whole point of me "owning" my information?
More likely that Google would buy them.
They're especially inaccurate for any product with mobile apps, since they have zero insight into that traffic. Nor do they properly extrapolate between the massively different traffic patterns of users with apps (which tends to be a lot stickier) vs web traffic.
Several times, people citing SimilarWeb numbers have argued with me about things where I had first-hand direct knowledge of the correct numbers (e.g., numbers involving a company I worked for). It's frustrating. These people sided with SimilarWeb because it's some source they can cite, nevermind the fact that it was complete garbage in these cases.
It can be surprisingly close