I disagree this happens to "all" apps, I have just looked at 5 different apps on 3 different phones and this is not the case only with the Facebook app. "It has nothing to do with cashed data this is simply not removing old versions of updates" : If this were the case then I would lose functionalities when deleting cache, which doesn't happen when I delete Facebook Cache. "For example update 1 has new options update 2 has the same options + a few extra , but it still keeps update 1 .. " This is also not true, when I look at the fb app the "base" app is arround 150-170mb. When deleting the app and reinstalling it, it still is 160mb. Furthermore in the Facebook app storage setting you can see the storage divided in: Application, data and Cache. And application storage stays consistent on my phones. You could always try and reset your phone if you think that would help, I think it won't. I would advice to buy a sd-card if you need space.
... View more