Comment by teddyfrozevelt

It's not really that bad. You are told the permissions requested by an app on installation:

  $ flatpak install flathub com.microsoft.Teams

  com.microsoft.Teams permissions:
      ipc     network     pcsc     pulseaudio     x11     devices     file access [1]     dbus access [2]     tags [3]
  
      [1] xdg-download
      [2] org.freedesktop.Notifications, org.freedesktop.secrets, org.gnome.SessionManager, org.kde.StatusNotifierWatcher
      [3] proprietary


          ID                           Branch          Op         Remote          Download
   1.     com.microsoft.Teams          stable          i          flathub         < 86.0 MB

  Proceed with these changes to the system installation? [Y/n]: 

and you can query an apps permissions at any time:

  $ flatpak info --show-permissions com.discordapp.Discord

  [Context]
  shared=network;ipc;
  sockets=x11;pulseaudio;
  devices=all;
  filesystems=xdg-download;xdg-pictures:ro;xdg-videos:ro;home;

  [Session Bus Policy]
  org.kde.StatusNotifierWatcher=talk
  org.freedesktop.Notifications=talk
  com.canonical.AppMenu.Registrar=talk
  com.canonical.indicator.application=talk
  com.canonical.Unity.LauncherEntry=talk

GNOME Software in GNOME 41 also has a much better list of permissions than the version shown in this article.

https://blogs.gnome.org/tbernard/2021/09/09/software-41-cont...