It’s not that they would necessarily cripple it, but they would “enhance” their instance of AP (the “extend” in EEE), “accidentally” making it incompatible with the rest of the Fediverse and thus creating an excuse to suddenly drop support for the Fediverse. At this point users in, say, Mastodon will have created some degree of dependency on users in Threads, and at that point people in there would be forced to move to Threads if they want to maintain a similar experience as before.
Not really the same thing, but I switched from Google Drive to Syncthing. It’s not as secure in terms of “chance of losing your data”, but I’m replicating data on my main PC, on my phone and on my RPi Zero and this is good enough for me, at least for now. Ideally I would periodically encrypt and upload every synced folder to the cloud (just because it’s encrypted), but that’s for another day.