why is it taking so long to download apps

Sorry, but a question like that is very difficult to answer. Even with a very fast Internet connection, any of the following could be the possible reason for the slow download performance:

1. Your local network
2. The overall state of the Internet between your local network and the app servers where you are downloading them from.
3. The app servers may be "busy" with many concurrent downloads being requested simultaneously.
4. The app is extremely popular or has recently been announced that it is available and your download is in a queue with all the other request.
5. Etc.

Would you please share your solution as it may help others with a similar issue?