You can now download from Amazon Prime Video!

Download Prime Videos from all Amazon Prime Video regional websites including the U.S. and Germany.
● Download videos with a high quality of 1080p.
● High-speed download: just 5 – 15 minutes per video.
● Manually select which audio and subtitles to download.

Currently, downloading from Amazon Prime Video, Netflix, Disney+ and HBO Max is supported.
More info here

The problem for some is that they spent their finances on another product that they will more the likely stay with that software because they also have a software to download Amazon Prime videos as well. But the problem with Amazon Prime is some are still paid so that will be harder if some wants the newer movies as well.