Not sure why is this being downvoted. Apple is currently selling 8 models across 4 lines (6s, 7, 8, X and SE), and the iPhone 6 line is still being sold by carriers. This is pretty much the first time when 8 primary models are available from Apple + at least 2 models are still being sold.

If the model trend continues to grow as it has been since the iPhone 6, there might be actually a need for device model emulation for development...