From u/johste over at r/MobileGaming from [this](https://www.reddit.com/r/MobileGaming/comments/hjyftc/why_do_i_have_to_download_data_for_most_mobile/) post;
>Developer here. This is called the “Getting a foot in the door” tactic. There are several reasons for it.
>
>1. Apple and Google has a very low limit for how big an app can be before their marketplace will warn or block the customer from downloading it while without wifi. Since a lot of people discover games while their commuting or otherwise without wifi this lets developers install an empty shell of their app to serve as a bookmark and reminder on your homescreen. Otherwise potential customers delay downloading and might have forgotten by the time they get home.
>
>2. If the first download of the app was huge, potential customers might cancel before it was finished thinking their internet is slow / faulty. That there is something wrong with the app or realize that it might be expensive to download without wifi.
>
>3. Having everyone on the same version is important in online games. Because these apps like to update frequently and Appstore/Google Play don’t update everyone’s app immediately when a new update is available. This stops you from having to manually go to the marketplace to look for an update every time you want to play the game.
>
>4. Having the ability update their app without you going to the marketplace allows them to add more content faster and make sure everyone is on the same version.
Latest Answers