Wait a minute, isn't this the main reason Google is blocking all offline extension installs across all platform soon and enforcing all installations to be done

Wait a minute, isn't this the main reason Google is blocking all offline extension installs across all platform soon and enforcing all installations to be done via its web store? Why is Dropbox wasting time on something that's about to be broken soon? Unless they have a deal with Google to allow this? If so, isn't that anti-competitive?