This is the biggest issue with window management on all new/mobile platforms, they can run multiple apps simultaneously but they can not run multiple instances

This is the biggest issue with window management on all new/mobile platforms, they can run multiple apps simultaneously but they can not run multiple instances of the same app! Compare the weather in two cities using the weather app, forget it. Compare two PDF documents with the office app, forget it. Compare two bus routes with your local public transport app, forget it. Why are we creating systems that are worse than what we already have.